Adding upstream version 2.12.1.upstream/2.12.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

46 files changed, 5170 insertions, 0 deletions

diff --git a/library/Icinga/Data/ConfigObject.php b/library/Icinga/Data/ConfigObject.php
new file mode 100644
index 0000000..c9a3134
--- /dev/null
+++ b/library/Icinga/Data/ConfigObject.php
@@ -0,0 +1,289 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Iterator;
+use ArrayAccess;
+use Icinga\Data\DataArray\ArrayDatasource;
+use Icinga\Exception\ProgrammingError;
+
+/**
+ * Container for configuration values
+ */
+class ConfigObject extends ArrayDatasource implements Iterator, ArrayAccess
+{
+    /**
+     * Create a new config
+     *
+     * @param   array   $data   The data to initialize the new config with
+     */
+    public function __construct(array $data = array())
+    {
+        // Convert all embedded arrays to ConfigObjects as well
+        foreach ($data as & $value) {
+            if (is_array($value)) {
+                $value = new static($value);
+            }
+        }
+
+        parent::__construct($data);
+    }
+
+    /**
+     * Deep clone this config
+     */
+    public function __clone()
+    {
+        $array = array();
+        foreach ($this->data as $key => $value) {
+            if ($value instanceof self) {
+                $array[$key] = clone $value;
+            } else {
+                $array[$key] = $value;
+            }
+        }
+
+        $this->data = $array;
+    }
+
+    /**
+     * Reset the current position of $this->data
+     *
+     * @return  void
+     */
+    public function rewind(): void
+    {
+        reset($this->data);
+    }
+
+    /**
+     * Return the section's or property's value of the current iteration
+     *
+     * @return  mixed
+     */
+    #[\ReturnTypeWillChange]
+    public function current()
+    {
+        return current($this->data);
+    }
+
+    /**
+     * Return whether the position of the current iteration is valid
+     *
+     * @return  bool
+     */
+    public function valid(): bool
+    {
+        return key($this->data) !== null;
+    }
+
+    /**
+     * Return the section's or property's name of the current iteration
+     *
+     * @return  string
+     */
+    public function key(): string
+    {
+        return key($this->data);
+    }
+
+    /**
+     * Advance the position of the current iteration and return the new section's or property's value
+     *
+     * @return  void
+     */
+    public function next(): void
+    {
+        next($this->data);
+    }
+
+    /**
+     * Return whether the given section or property is set
+     *
+     * @param   string  $key    The name of the section or property
+     *
+     * @return  bool
+     */
+    public function __isset($key)
+    {
+        return isset($this->data[$key]);
+    }
+
+    /**
+     * Return the value for the given property or the config for the given section
+     *
+     * @param   string  $key    The name of the property or section
+     *
+     * @return  mixed|NULL      The value or NULL in case $key does not exist
+     */
+    public function __get($key)
+    {
+        return $this->get($key);
+    }
+
+    /**
+     * Add a new property or section
+     *
+     * @param   string  $key    The name of the new property or section
+     * @param   mixed   $value  The value to set for the new property or section
+     */
+    public function __set($key, $value)
+    {
+        if (is_array($value)) {
+            $this->data[$key] = new static($value);
+        } else {
+            $this->data[$key] = $value;
+        }
+    }
+
+    /**
+     * Remove the given property or section
+     *
+     * @param   string  $key    The property or section to remove
+     */
+    public function __unset($key)
+    {
+        unset($this->data[$key]);
+    }
+
+    /**
+     * Return whether the given section or property is set
+     *
+     * @param   string  $key    The name of the section or property
+     *
+     * @return  bool
+     */
+    public function offsetExists($key): bool
+    {
+        return isset($this->$key);
+    }
+
+    /**
+     * Return the value for the given property or the config for the given section
+     *
+     * @param   string  $key    The name of the property or section
+     *
+     * @return  ?mixed      The value or NULL in case $key does not exist
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($key)
+    {
+        return $this->get($key);
+    }
+
+    /**
+     * Add a new property or section
+     *
+     * @param   string  $key        The name of the new property or section
+     * @param   mixed   $value      The value to set for the new property or section
+     *
+     * @throws  ProgrammingError    If the key is null
+     */
+    public function offsetSet($key, $value): void
+    {
+        if ($key === null) {
+            throw new ProgrammingError('Appending values without an explicit key is not supported');
+        }
+
+        $this->$key = $value;
+    }
+
+    /**
+     * Remove the given property or section
+     *
+     * @param   string  $key    The property or section to remove
+     */
+    public function offsetUnset($key): void
+    {
+        unset($this->$key);
+    }
+
+    /**
+     * Return whether this config has any data
+     *
+     * @return  bool
+     */
+    public function isEmpty()
+    {
+        return empty($this->data);
+    }
+
+    /**
+     * Return the value for the given property or the config for the given section
+     *
+     * @param   string  $key        The name of the property or section
+     * @param   mixed   $default    The value to return in case the property or section is missing
+     *
+     * @return  mixed
+     */
+    public function get($key, $default = null)
+    {
+        if (array_key_exists($key, $this->data)) {
+            return $this->data[$key];
+        }
+
+        return $default;
+    }
+
+    /**
+     * Return all section and property names
+     *
+     * @return  array
+     */
+    public function keys()
+    {
+        return array_keys($this->data);
+    }
+
+    /**
+     * Return this config's data as associative array
+     *
+     * @return  array
+     */
+    public function toArray()
+    {
+        $array = array();
+        foreach ($this->data as $key => $value) {
+            if ($value instanceof self) {
+                $array[$key] = $value->toArray();
+            } else {
+                $array[$key] = $value;
+            }
+        }
+
+        return $array;
+    }
+
+    /**
+     * Merge the given data with this config
+     *
+     * @param   array|ConfigObject $data An array or a config
+     *
+     * @return  $this
+     */
+    public function merge($data)
+    {
+        if ($data instanceof self) {
+            $data = $data->toArray();
+        }
+
+        foreach ($data as $key => $value) {
+            if (array_key_exists($key, $this->data)) {
+                if (is_array($value)) {
+                    if ($this->data[$key] instanceof self) {
+                        $this->data[$key]->merge($value);
+                    } else {
+                        $this->data[$key] = new static($value);
+                    }
+                } else {
+                    $this->data[$key] = $value;
+                }
+            } else {
+                $this->data[$key] = is_array($value) ? new static($value) : $value;
+            }
+        }
+
+        return $this;
+    }
+}
diff --git a/library/Icinga/Data/ConnectionInterface.php b/library/Icinga/Data/ConnectionInterface.php
new file mode 100644
index 0000000..bd7d026
--- /dev/null
+++ b/library/Icinga/Data/ConnectionInterface.php
@@ -0,0 +1,8 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+interface ConnectionInterface extends Selectable, Queryable
+{
+}
diff --git a/library/Icinga/Data/DataArray/ArrayDatasource.php b/library/Icinga/Data/DataArray/ArrayDatasource.php
new file mode 100644
index 0000000..e300616
--- /dev/null
+++ b/library/Icinga/Data/DataArray/ArrayDatasource.php
@@ -0,0 +1,292 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\DataArray;
+
+use ArrayIterator;
+use Icinga\Data\Selectable;
+use Icinga\Data\SimpleQuery;
+
+class ArrayDatasource implements Selectable
+{
+    /**
+     * The array being used as data source
+     *
+     * @var array
+     */
+    protected $data;
+
+    /**
+     * The current result
+     *
+     * @var array
+     */
+    protected $result;
+
+    /**
+     * The result of a counted query
+     *
+     * @var int
+     */
+    protected $count;
+
+    /**
+     * The name of the column to map array keys on
+     *
+     * In case the array being used as data source provides keys of type string,this name
+     * will be used to set such as column on each row, if the column is not set already.
+     *
+     * @var string
+     */
+    protected $keyColumn;
+
+    /**
+     * Create a new data source for the given array
+     *
+     * @param   array   $data   The array you're going to use as a data source
+     */
+    public function __construct(array $data)
+    {
+        $this->data = $data;
+    }
+
+    /**
+     * Set the name of the column to map array keys on
+     *
+     * @param   string  $name
+     *
+     * @return  $this
+     */
+    public function setKeyColumn($name)
+    {
+        $this->keyColumn = $name;
+        return $this;
+    }
+
+    /**
+     * Return the name of the column to map array keys on
+     *
+     * @return  string
+     */
+    public function getKeyColumn()
+    {
+        return $this->keyColumn;
+    }
+
+    /**
+     * Provide a query for this data source
+     *
+     * @return  SimpleQuery
+     */
+    public function select()
+    {
+        return new SimpleQuery(clone $this);
+    }
+
+    /**
+     * Fetch and return all rows of the given query's result set using an iterator
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  ArrayIterator
+     */
+    public function query(SimpleQuery $query)
+    {
+        return new ArrayIterator($this->fetchAll($query));
+    }
+
+    /**
+     * Fetch and return a column of all rows of the result set as an array
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  array
+     */
+    public function fetchColumn(SimpleQuery $query)
+    {
+        $result = array();
+        foreach ($this->getResult($query) as $row) {
+            $arr = (array) $row;
+            $result[] = array_shift($arr);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Fetch and return all rows of the given query's result as a flattened key/value based array
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  array
+     */
+    public function fetchPairs(SimpleQuery $query)
+    {
+        $result = array();
+        $keys = null;
+        foreach ($this->getResult($query) as $row) {
+            if ($keys === null) {
+                $keys = array_keys((array) $row);
+                if (count($keys) < 2) {
+                    $keys[1] = $keys[0];
+                }
+            }
+
+            $result[$row->{$keys[0]}] = $row->{$keys[1]};
+        }
+
+        return $result;
+    }
+
+    /**
+     * Fetch and return the first row of the given query's result
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  object|false    The row or false in case the result is empty
+     */
+    public function fetchRow(SimpleQuery $query)
+    {
+        $result = $this->getResult($query);
+        if (empty($result)) {
+            return false;
+        }
+
+        return array_shift($result);
+    }
+
+    /**
+     * Fetch and return all rows of the given query's result as an array
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  array
+     */
+    public function fetchAll(SimpleQuery $query)
+    {
+        return $this->getResult($query);
+    }
+
+    /**
+     * Count all rows of the given query's result
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  int
+     */
+    public function count(SimpleQuery $query)
+    {
+        if ($this->count === null) {
+            $this->count = count($this->createResult($query));
+        }
+
+        return $this->count;
+    }
+
+    /**
+     * Create and return the result for the given query
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  array
+     */
+    protected function createResult(SimpleQuery $query)
+    {
+        $columns = $query->getColumns();
+        $filter = $query->getFilter();
+        $offset = $query->hasOffset() ? $query->getOffset() : 0;
+        $limit = $query->hasLimit() ? $query->getLimit() : 0;
+        $data = $this->data;
+
+        if ($query->hasOrder()) {
+            uasort($data, [$query, 'compare']);
+        }
+
+        $foundStringKey = false;
+        $result = [];
+        $skipped = 0;
+        foreach ($data as $key => $row) {
+            if ($this->keyColumn !== null && !isset($row->{$this->keyColumn})) {
+                $row = clone $row; // Make sure that this won't affect the actual data
+                $row->{$this->keyColumn} = $key;
+            }
+
+            if (! $filter->matches($row)) {
+                continue;
+            } elseif ($skipped < $offset) {
+                $skipped++;
+                continue;
+            }
+
+            // Get only desired columns if asked so
+            if (! empty($columns)) {
+                $filteredRow = (object) array();
+                foreach ($columns as $alias => $name) {
+                    if (! is_string($alias)) {
+                        $alias = $name;
+                    }
+
+                    if (isset($row->$name)) {
+                        $filteredRow->$alias = $row->$name;
+                    } else {
+                        $filteredRow->$alias = null;
+                    }
+                }
+            } else {
+                $filteredRow = $row;
+            }
+
+            $foundStringKey |= is_string($key);
+            $result[$key] = $filteredRow;
+
+            if (count($result) === $limit) {
+                break;
+            }
+        }
+
+        if (! $foundStringKey) {
+            $result = array_values($result);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Return whether a query result exists
+     *
+     * @return  bool
+     */
+    protected function hasResult()
+    {
+        return $this->result !== null;
+    }
+
+    /**
+     * Set the current result
+     *
+     * @param   array   $result
+     *
+     * @return  $this
+     */
+    protected function setResult(array $result)
+    {
+        $this->result = $result;
+        return $this;
+    }
+
+    /**
+     * Return the result for the given query
+     *
+     * @param   SimpleQuery     $query
+     *
+     * @return  array
+     */
+    protected function getResult(SimpleQuery $query)
+    {
+        if (! $this->hasResult()) {
+            $this->setResult($this->createResult($query));
+        }
+
+        return $this->result;
+    }
+}
diff --git a/library/Icinga/Data/Db/DbConnection.php b/library/Icinga/Data/Db/DbConnection.php
new file mode 100644
index 0000000..fc6814d
--- /dev/null
+++ b/library/Icinga/Data/Db/DbConnection.php
@@ -0,0 +1,655 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Db;
+
+use DateTime;
+use DateTimeZone;
+use Exception;
+use Icinga\Data\Filter\FilterEqual;
+use Icinga\Data\Filter\FilterNotEqual;
+use Icinga\Data\Inspectable;
+use Icinga\Data\Inspection;
+use PDO;
+use Iterator;
+use Zend_Db;
+use Zend_Db_Expr;
+use Icinga\Data\ConfigObject;
+use Icinga\Data\Extensible;
+use Icinga\Data\Filter\Filter;
+use Icinga\Data\Filter\FilterAnd;
+use Icinga\Data\Filter\FilterNot;
+use Icinga\Data\Filter\FilterOr;
+use Icinga\Data\Reducible;
+use Icinga\Data\ResourceFactory;
+use Icinga\Data\Selectable;
+use Icinga\Data\Updatable;
+use Icinga\Exception\ConfigurationError;
+use Icinga\Exception\ProgrammingError;
+
+/**
+ * Encapsulate database connections and query creation
+ */
+class DbConnection implements Selectable, Extensible, Updatable, Reducible, Inspectable
+{
+    /**
+     * Connection config
+     *
+     * @var ConfigObject
+     */
+    private $config;
+
+    /**
+     * Database type
+     *
+     * @var string
+     */
+    private $dbType;
+
+    /**
+     * @var \Zend_Db_Adapter_Abstract
+     */
+    private $dbAdapter;
+
+    /**
+     * Table prefix
+     *
+     * @var string
+     */
+    private $tablePrefix = '';
+
+    private static $genericAdapterOptions = array(
+        Zend_Db::AUTO_QUOTE_IDENTIFIERS => false,
+        Zend_Db::CASE_FOLDING           => Zend_Db::CASE_LOWER
+    );
+
+    private static $driverOptions = array(
+        PDO::ATTR_TIMEOUT    => 10,
+        PDO::ATTR_CASE       => PDO::CASE_LOWER,
+        PDO::ATTR_ERRMODE    => PDO::ERRMODE_EXCEPTION
+    );
+
+    /**
+     * Create a new connection object
+     *
+     * @param ConfigObject $config
+     */
+    public function __construct(ConfigObject $config = null)
+    {
+        $this->config = $config;
+        $this->connect();
+    }
+
+    /**
+     * Provide a query on this connection
+     *
+     * @return  DbQuery
+     */
+    public function select()
+    {
+        return new DbQuery($this);
+    }
+
+    /**
+     * Fetch and return all rows of the given query's result set using an iterator
+     *
+     * @param   DbQuery     $query
+     *
+     * @return  Iterator
+     */
+    public function query(DbQuery $query)
+    {
+        return $query->getSelectQuery()->query();
+    }
+
+    /**
+     * Get the connection configuration
+     *
+     * @return  ConfigObject
+     */
+    public function getConfig()
+    {
+        return $this->config;
+    }
+
+    /**
+     * Getter for database type
+     *
+     * @return string
+     */
+    public function getDbType()
+    {
+        return $this->dbType;
+    }
+
+    /**
+     * Getter for the Zend_Db_Adapter
+     *
+     * @return \Zend_Db_Adapter_Abstract
+     */
+    public function getDbAdapter()
+    {
+        return $this->dbAdapter;
+    }
+
+    /**
+     * Create a new connection
+     */
+    private function connect()
+    {
+        $genericAdapterOptions  = self::$genericAdapterOptions;
+        $driverOptions          = self::$driverOptions;
+        $adapterParamaters      = array(
+            'host'              => $this->config->host,
+            'username'          => $this->config->username,
+            'password'          => $this->config->password,
+            'dbname'            => $this->config->dbname,
+            'charset'           => $this->config->charset ?: null,
+            'options'           => & $genericAdapterOptions,
+            'driver_options'    => & $driverOptions
+        );
+        $this->dbType = strtolower($this->config->get('db', 'mysql'));
+        switch ($this->dbType) {
+            case 'mssql':
+                $adapter = 'Pdo_Mssql';
+                $pdoType = $this->config->get('pdoType');
+                if (empty($pdoType)) {
+                    if (extension_loaded('sqlsrv')) {
+                        $adapter = 'Sqlsrv';
+                    } else {
+                        $pdoType = 'dblib';
+                    }
+                }
+                if ($pdoType === 'dblib') {
+                    // Driver does not support setting attributes
+                    unset($adapterParamaters['options']);
+                    unset($adapterParamaters['driver_options']);
+                }
+                if (! empty($pdoType)) {
+                    $adapterParamaters['pdoType'] = $pdoType;
+                }
+                $defaultPort = 1433;
+                break;
+            case 'mysql':
+                $adapter = 'Pdo_Mysql';
+                if ($this->config->use_ssl) {
+                    # The presence of these keys as empty strings or null cause non-ssl connections to fail
+                    if ($this->config->ssl_key) {
+                        $adapterParamaters['driver_options'][PDO::MYSQL_ATTR_SSL_KEY] = $this->config->ssl_key;
+                    }
+                    if ($this->config->ssl_cert) {
+                        $adapterParamaters['driver_options'][PDO::MYSQL_ATTR_SSL_CERT] = $this->config->ssl_cert;
+                    }
+                    if ($this->config->ssl_ca) {
+                        $adapterParamaters['driver_options'][PDO::MYSQL_ATTR_SSL_CA] = $this->config->ssl_ca;
+                    }
+                    if ($this->config->ssl_capath) {
+                        $adapterParamaters['driver_options'][PDO::MYSQL_ATTR_SSL_CAPATH] = $this->config->ssl_capath;
+                    }
+                    if ($this->config->ssl_cipher) {
+                        $adapterParamaters['driver_options'][PDO::MYSQL_ATTR_SSL_CIPHER] = $this->config->ssl_cipher;
+                    }
+                    if (defined('PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT')
+                        && $this->config->ssl_do_not_verify_server_cert
+                    ) {
+                        $adapterParamaters['driver_options'][PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT] = false;
+                    }
+                }
+                /*
+                 * Set MySQL server SQL modes to behave as closely as possible to Oracle and PostgreSQL. Note that the
+                 * ONLY_FULL_GROUP_BY mode is left on purpose because MySQL requires you to specify all non-aggregate
+                 * columns in the group by list even if the query is grouped by the master table's primary key which is
+                 * valid ANSI SQL though. Further in that case the query plan would suffer if you add more columns to
+                 * the group by list.
+                 */
+                $driverOptions[PDO::MYSQL_ATTR_INIT_COMMAND] =
+                    'SET SESSION SQL_MODE=\'STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,'
+                    . 'ANSI_QUOTES,PIPES_AS_CONCAT,NO_ENGINE_SUBSTITUTION\'';
+                if (isset($adapterParamaters['charset'])) {
+                    $driverOptions[PDO::MYSQL_ATTR_INIT_COMMAND] .= ', NAMES ' . $adapterParamaters['charset'];
+                    if (trim($adapterParamaters['charset']) === 'latin1') {
+                        // Required for MySQL 8+ because we need PIPES_AS_CONCAT and
+                        // have several columns with explicit COLLATE instructions
+                        $driverOptions[PDO::MYSQL_ATTR_INIT_COMMAND] .= ' COLLATE latin1_general_ci';
+                    }
+
+                    unset($adapterParamaters['charset']);
+                }
+
+                $driverOptions[PDO::MYSQL_ATTR_INIT_COMMAND] .= ", time_zone='" . $this->defaultTimezoneOffset() . "'";
+                $driverOptions[PDO::MYSQL_ATTR_INIT_COMMAND] .=';';
+                $defaultPort = 3306;
+                break;
+            case 'oci':
+                $adapter = 'Oracle';
+                unset($adapterParamaters['options']);
+                unset($adapterParamaters['driver_options']);
+                $adapterParamaters['driver_options'] = array(
+                    'lob_as_string' => true
+                );
+                $defaultPort = 1521;
+                break;
+            case 'oracle':
+                $adapter = 'Pdo_Oci';
+                $defaultPort = 1521;
+
+                // remove host parameter when not configured
+                if (empty($this->config->host)) {
+                    unset($adapterParamaters['host']);
+                }
+                break;
+            case 'pgsql':
+                $adapter = 'Pdo_Pgsql';
+                $defaultPort = 5432;
+                break;
+            case 'ibm':
+                $adapter = 'Pdo_Ibm';
+                $defaultPort = 50000;
+                break;
+            case 'sqlite':
+                $adapter = 'Pdo_Sqlite';
+                $defaultPort = 0; // Dummy port because a value is required
+                break;
+            default:
+                throw new ConfigurationError(
+                    'Backend "%s" is not supported',
+                    $this->dbType
+                );
+        }
+        $adapterParamaters['port'] = $this->config->get('port', $defaultPort);
+        $this->dbAdapter = Zend_Db::factory($adapter, $adapterParamaters);
+        $this->dbAdapter->setFetchMode(Zend_Db::FETCH_OBJ);
+        // TODO(el/tg): The profiler is disabled per default, why do we disable the profiler explicitly?
+        $this->dbAdapter->getProfiler()->setEnabled(false);
+    }
+
+    public static function fromResourceName($name)
+    {
+        return new static(ResourceFactory::getResourceConfig($name));
+    }
+
+    /**
+     * Getter for the table prefix
+     *
+     * @return string
+     */
+    public function getTablePrefix()
+    {
+        return $this->tablePrefix;
+    }
+
+    /**
+     * Setter for the table prefix
+     *
+     * @param   string $prefix
+     *
+     * @return  $this
+     */
+    public function setTablePrefix($prefix)
+    {
+        $this->tablePrefix = $prefix;
+        return $this;
+    }
+
+    /**
+     * Get offset from the current default timezone to GMT
+     *
+     * @return string
+     */
+    protected function defaultTimezoneOffset()
+    {
+        $tz = new DateTimeZone(date_default_timezone_get());
+        $offset = $tz->getOffset(new DateTime());
+        $prefix = $offset >= 0 ? '+' : '-';
+        $offset = abs($offset);
+        $hours = (int) floor($offset / 3600);
+        $minutes = (int) floor(($offset % 3600) / 60);
+        return sprintf('%s%d:%02d', $prefix, $hours, $minutes);
+    }
+
+    /**
+     * Count all rows of the result set
+     *
+     * @param   DbQuery     $query
+     *
+     * @return  int
+     */
+    public function count(DbQuery $query)
+    {
+        return (int) $this->dbAdapter->fetchOne($query->getCountQuery());
+    }
+
+    /**
+     * Retrieve an array containing all rows of the result set
+     *
+     * @param   DbQuery $query
+     *
+     * @return  array
+     */
+    public function fetchAll(DbQuery $query)
+    {
+        return $this->dbAdapter->fetchAll($query->getSelectQuery());
+    }
+
+    /**
+     * Fetch the first row of the result set
+     *
+     * @param   DbQuery $query
+     *
+     * @return  mixed
+     */
+    public function fetchRow(DbQuery $query)
+    {
+        return $this->dbAdapter->fetchRow($query->getSelectQuery());
+    }
+
+    /**
+     * Fetch the first column of all rows of the result set as an array
+     *
+     * @param   DbQuery   $query
+     *
+     * @return  array
+     */
+    public function fetchColumn(DbQuery $query)
+    {
+        return $this->dbAdapter->fetchCol($query->getSelectQuery());
+    }
+
+    /**
+     * Fetch the first column of the first row of the result set
+     *
+     * @param   DbQuery $query
+     *
+     * @return  string
+     */
+    public function fetchOne(DbQuery $query)
+    {
+        return $this->dbAdapter->fetchOne($query->getSelectQuery());
+    }
+
+    /**
+     * Fetch all rows of the result set as an array of key-value pairs
+     *
+     * The first column is the key, the second column is the value.
+     *
+     * @param   DbQuery $query
+     *
+     * @return  array
+     */
+    public function fetchPairs(DbQuery $query)
+    {
+        return $this->dbAdapter->fetchPairs($query->getSelectQuery());
+    }
+
+    /**
+     * Insert a table row with the given data
+     *
+     * Note that the base implementation does not perform any quoting on the $table argument.
+     * Pass an array with a column name (the same as in $bind) and a PDO::PARAM_* constant as value
+     * as third parameter $types to define a different type than string for a particular column.
+     *
+     * @param   string  $table
+     * @param   array   $bind
+     * @param   array   $types
+     *
+     * @return  int             The number of affected rows
+     */
+    public function insert($table, array $bind, array $types = array())
+    {
+        $columns = $values = array();
+        foreach ($bind as $column => $value) {
+            $columns[] = $column;
+            if ($value instanceof Zend_Db_Expr) {
+                $values[] = (string) $value;
+                unset($bind[$column]);
+            } else {
+                $values[] = ':' . $column;
+            }
+        }
+
+        $sql = 'INSERT INTO ' . $table
+            . ' (' . join(', ', $columns) . ') '
+            . 'VALUES (' . join(', ', $values) . ')';
+        $statement = $this->dbAdapter->prepare($sql);
+
+        foreach ($bind as $column => $value) {
+            $type = isset($types[$column]) ? $types[$column] : PDO::PARAM_STR;
+            $statement->bindValue(':' . $column, $value, $type);
+        }
+
+        $statement->execute();
+        return $statement->rowCount();
+    }
+
+    /**
+     * Update table rows with the given data, optionally limited by using a filter
+     *
+     * Note that the base implementation does not perform any quoting on the $table argument.
+     * Pass an array with a column name (the same as in $bind) and a PDO::PARAM_* constant as value
+     * as fourth parameter $types to define a different type than string for a particular column.
+     *
+     * @param   string  $table
+     * @param   array   $bind
+     * @param   Filter  $filter
+     * @param   array   $types
+     *
+     * @return  int             The number of affected rows
+     */
+    public function update($table, array $bind, Filter $filter = null, array $types = array())
+    {
+        $set = array();
+        foreach ($bind as $column => $value) {
+            if ($value instanceof Zend_Db_Expr) {
+                $set[] = $column . ' = ' . $value;
+                unset($bind[$column]);
+            } else {
+                $set[] = $column . ' = :' . $column;
+            }
+        }
+
+        $sql = 'UPDATE ' . $table
+            . ' SET ' . join(', ', $set)
+            . ($filter ? ' WHERE ' . $this->renderFilter($filter) : '');
+        $statement = $this->dbAdapter->prepare($sql);
+
+        foreach ($bind as $column => $value) {
+            $type = isset($types[$column]) ? $types[$column] : PDO::PARAM_STR;
+            $statement->bindValue(':' . $column, $value, $type);
+        }
+
+        $statement->execute();
+        return $statement->rowCount();
+    }
+
+    /**
+     * Delete table rows, optionally limited by using a filter
+     *
+     * @param   string  $table
+     * @param   Filter  $filter
+     *
+     * @return  int             The number of affected rows
+     */
+    public function delete($table, Filter $filter = null)
+    {
+        return $this->dbAdapter->delete($table, $filter ? $this->renderFilter($filter) : '');
+    }
+
+    /**
+     * Render and return the given filter as SQL-WHERE clause
+     *
+     * @param   Filter  $filter
+     *
+     * @return  string
+     */
+    public function renderFilter(Filter $filter, $level = 0)
+    {
+        // TODO: This is supposed to supersede DbQuery::renderFilter()
+        $where = '';
+        if ($filter->isChain()) {
+            if ($filter instanceof FilterAnd) {
+                $operator = ' AND ';
+            } elseif ($filter instanceof FilterOr) {
+                $operator = ' OR ';
+            } elseif ($filter instanceof FilterNot) {
+                $operator = ' AND ';
+                $where .= ' NOT ';
+            } else {
+                throw new ProgrammingError('Cannot render filter: %s', get_class($filter));
+            }
+
+            if (! $filter->isEmpty()) {
+                $parts = array();
+                foreach ($filter->filters() as $filterPart) {
+                    $part = $this->renderFilter($filterPart, $level + 1);
+                    if ($part) {
+                        $parts[] = $part;
+                    }
+                }
+
+                if (! empty($parts)) {
+                    if ($level > 0) {
+                        $where .= ' (' . implode($operator, $parts) . ') ';
+                    } else {
+                        $where .= implode($operator, $parts);
+                    }
+                }
+            } else {
+                return ''; // Explicitly return the empty string due to the FilterNot case
+            }
+        } else {
+            $where .= $this->renderFilterExpression($filter);
+        }
+
+        return $where;
+    }
+
+    /**
+     * Render and return the given filter expression
+     *
+     * @param   Filter  $filter
+     *
+     * @return  string
+     */
+    protected function renderFilterExpression(Filter $filter)
+    {
+        $column = $filter->getColumn();
+        $sign = $filter->getSign();
+        $value = $filter->getExpression();
+
+        if (is_array($value)) {
+            $comp = [];
+            $pattern = [];
+            foreach ($value as $val) {
+                if (strpos($val, '*') === false) {
+                    $comp[] = $val;
+                } else {
+                    $pattern[] = $this->renderFilterExpression(Filter::expression($column, $sign, $val));
+                }
+            }
+
+            $sql = $pattern;
+            if ($sign === '=') {
+                if (! empty($comp)) {
+                    $sql[] = $column . ' IN (' . $this->dbAdapter->quote($comp) . ')';
+                }
+
+                $operator = 'OR';
+            } elseif ($sign === '!=') {
+                if (! empty($comp)) {
+                    $sql[] = sprintf(
+                        '(%1$s NOT IN (%2$s) OR %1$s IS NULL)',
+                        $column,
+                        $this->dbAdapter->quote($comp)
+                    );
+                }
+
+                $operator = 'AND';
+            } else {
+                throw new ProgrammingError(
+                    'Unable to render array expressions with operators other than equal or not equal'
+                );
+            }
+
+            return count($sql) === 1 ? $sql[0] : '(' . implode(" $operator ", $sql) . ')';
+        } elseif ($sign === '='
+            && ! $filter instanceof FilterEqual
+            && $value !== null
+            && strpos($value, '*') !== false
+        ) {
+            if ($value === '*') {
+                return $column . ' IS NOT NULL';
+            }
+
+            return $column . ' LIKE ' . $this->dbAdapter->quote(preg_replace('~\*~', '%', $value));
+        } elseif ($sign === '!='
+            && ! $filter instanceof FilterNotEqual
+            && $value !== null
+            && strpos($value, '*') !== false
+        ) {
+            if ($value === '*') {
+                return $column . ' IS NULL';
+            }
+
+            return sprintf(
+                '(%1$s NOT LIKE %2$s OR %1$s IS NULL)',
+                $column,
+                $this->dbAdapter->quote(preg_replace('~\*~', '%', $value))
+            );
+        } elseif ($sign === '!=') {
+            return sprintf('(%1$s != %2$s OR %1$s IS NULL)', $column, $this->dbAdapter->quote($value));
+        } else {
+            return sprintf('%s %s %s', $column, $sign, $this->dbAdapter->quote($value));
+        }
+    }
+
+    public function inspect()
+    {
+        $insp = new Inspection('Db Connection');
+        try {
+            $this->getDbAdapter()->getConnection();
+            $config = $this->dbAdapter->getConfig();
+            $insp->write(sprintf(
+                'Connection to %s as %s on %s:%s successful',
+                $config['dbname'],
+                $config['username'],
+                array_key_exists('host', $config) ? $config['host'] : '(none)',
+                $config['port']
+            ));
+            switch ($this->dbType) {
+                case 'mysql':
+                    $rows = $this->dbAdapter->query(
+                        'SHOW VARIABLES WHERE variable_name ' .
+                        'IN (\'version\', \'protocol_version\', \'version_compile_os\', \'have_ssl\');'
+                    )->fetchAll();
+                    $sqlinsp = new Inspection('MySQL');
+                    $hasSsl = false;
+                    foreach ($rows as $row) {
+                        $sqlinsp->write($row->variable_name . ': ' . $row->value);
+                        if ($row->variable_name === 'have_ssl' && $row->value === 'YES') {
+                            $hasSsl = true;
+                        }
+                    }
+                    if ($hasSsl) {
+                        $ssl_rows = $this->dbAdapter->query(
+                            'SHOW STATUS WHERE variable_name ' .
+                            'IN (\'Ssl_Cipher\');'
+                        )->fetchAll();
+                        foreach ($ssl_rows as $ssl_row) {
+                            $sqlinsp->write($ssl_row->variable_name . ': ' . $ssl_row->value);
+                        }
+                    }
+                    $insp->write($sqlinsp);
+                    break;
+                case 'pgsql':
+                    $row = $this->dbAdapter->query('SELECT version();')->fetchAll();
+                    $sqlinsp = new Inspection('PostgreSQL');
+                    $sqlinsp->write($row[0]->version);
+                    $insp->write($sqlinsp);
+                    break;
+            }
+        } catch (Exception $e) {
+            return $insp->error(sprintf('Connection failed %s', $e->getMessage()));
+        }
+        return $insp;
+    }
+}
diff --git a/library/Icinga/Data/Db/DbQuery.php b/library/Icinga/Data/Db/DbQuery.php
new file mode 100644
index 0000000..ff1d131
--- /dev/null
+++ b/library/Icinga/Data/Db/DbQuery.php
@@ -0,0 +1,565 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Db;
+
+use DateInterval;
+use DateTime;
+use DateTimeZone;
+use Exception;
+use Icinga\Data\Filter\Filter;
+use Zend_Db_Adapter_Abstract;
+use Zend_Db_Expr;
+use Zend_Db_Select;
+use Icinga\Application\Logger;
+use Icinga\Data\SimpleQuery;
+use Icinga\Exception\ProgrammingError;
+use Icinga\Exception\QueryException;
+
+/**
+ * Database query class
+ */
+class DbQuery extends SimpleQuery
+{
+    /**
+     * @var Zend_Db_Adapter_Abstract
+     */
+    protected $db;
+
+    /**
+     * Whether or not the query is a sub query
+     *
+     * Sub queries are automatically wrapped in parentheses
+     *
+     * @var bool
+     */
+    protected $isSubQuery = false;
+
+    /**
+     * Select query
+     *
+     * @var Zend_Db_Select
+     */
+    protected $select;
+
+    /**
+     * Whether to use a subquery for counting
+     *
+     * When the query is distinct or has a HAVING or GROUP BY clause this must be set to true
+     *
+     * @var bool
+     */
+    protected $useSubqueryCount = false;
+
+    /**
+     * Count query result
+     *
+     * Count queries are only executed once
+     *
+     * @var int
+     */
+    protected $count;
+
+    /**
+     * GROUP BY clauses
+     *
+     * @var string|array
+     */
+    protected $group;
+
+    protected function init()
+    {
+        $this->db = $this->ds->getDbAdapter();
+        $this->select = $this->db->select();
+        parent::init();
+    }
+
+    /**
+     * Get whether or not the query is a sub query
+     */
+    public function getIsSubQuery()
+    {
+        return $this->isSubQuery;
+    }
+
+    /**
+     * Set whether or not the query is a sub query
+     *
+     * @param   bool $isSubQuery
+     *
+     * @return  $this
+     */
+    public function setIsSubQuery($isSubQuery = true)
+    {
+        $this->isSubQuery = (bool) $isSubQuery;
+        return $this;
+    }
+
+    public function setUseSubqueryCount($useSubqueryCount = true)
+    {
+        $this->useSubqueryCount = $useSubqueryCount;
+        return $this;
+    }
+
+    public function from($target, array $fields = null)
+    {
+        parent::from($target, $fields);
+        $this->select->from($this->target, array());
+        return $this;
+    }
+
+    public function where($condition, $value = null)
+    {
+        // $this->count = $this->select = null;
+        return parent::where($condition, $value);
+    }
+
+    public function addFilter(Filter $filter)
+    {
+        $this->expressionsToTimestamp($filter);
+        return parent::addFilter($filter);
+    }
+
+    private function expressionsToTimestamp(Filter $filter)
+    {
+        if ($filter->isChain()) {
+            foreach ($filter->filters() as $child) {
+                $this->expressionsToTimestamp($child);
+            }
+        } elseif ($this->isTimestamp($filter->getColumn())) {
+            $filter->setExpression($this->valueToTimestamp($filter->getExpression()));
+        }
+    }
+
+    protected function dbSelect()
+    {
+        return clone $this->select;
+    }
+
+    /**
+     * Return the underlying select
+     *
+     * @return  Zend_Db_Select
+     */
+    public function select()
+    {
+        return $this->select;
+    }
+
+    /**
+     * Get the select query
+     *
+     * Applies order and limit if any
+     *
+     * @return Zend_Db_Select
+     */
+    public function getSelectQuery()
+    {
+        $select = $this->dbSelect();
+        // Add order fields to select for postgres distinct queries (#6351)
+        if ($this->hasOrder()
+            && $this->getDatasource()->getDbType() === 'pgsql'
+            && $select->getPart(Zend_Db_Select::DISTINCT) === true) {
+            foreach ($this->getOrder() as $fieldAndDirection) {
+                if (array_search($fieldAndDirection[0], $this->columns, true) === false) {
+                    $this->columns[] = $fieldAndDirection[0];
+                }
+            }
+        }
+
+        $group = $this->getGroup();
+        if ($group) {
+            $select->group($group);
+        }
+
+        if (! empty($this->columns)) {
+            $select->columns($this->columns);
+        }
+
+        $this->applyFilterSql($select);
+
+        if ($this->hasLimit() || $this->hasOffset()) {
+            $select->limit($this->getLimit(), $this->getOffset());
+        }
+        if ($this->hasOrder()) {
+            foreach ($this->getOrder() as $fieldAndDirection) {
+                $select->order(
+                    $fieldAndDirection[0] . ' ' . $fieldAndDirection[1]
+                );
+            }
+        }
+
+        return $select;
+    }
+
+    protected function applyFilterSql($select)
+    {
+        $where = $this->getDatasource()->renderFilter($this->filter);
+        if ($where !== '') {
+            $select->where($where);
+        }
+    }
+
+    protected function escapeForSql($value)
+    {
+        // bindParam? bindValue?
+        if (is_array($value)) {
+            $ret = array();
+            foreach ($value as $val) {
+                $ret[] = $this->escapeForSql($val);
+            }
+            return implode(', ', $ret);
+        } else {
+            //if (preg_match('/^\d+$/', $value)) {
+            //    return $value;
+            //} else {
+                return $this->db->quote($value);
+            //}
+        }
+    }
+
+    protected function escapeWildcards($value)
+    {
+        return preg_replace('/\*/', '%', $value);
+    }
+
+    protected function valueToTimestamp($value)
+    {
+        if (is_string($value)) {
+            if (ctype_digit($value)) {
+                $value = (int) $value;
+            } else {
+                $value = strtotime($value);
+            }
+        } elseif (! is_int($value)) {
+            $value = (int) $value;
+        }
+
+        return $value;
+    }
+
+    /**
+     * Render the given timestamp based on the local timezone
+     *
+     * Since {@see DbConnection::defaultTimezoneOffset()} tells the database the timezone with just an offset,
+     * this will prepare the rendered value in a way that it plays fine with daylight savings.
+     *
+     * @param int $value
+     * @return string
+     */
+    protected function timestampForSql($value)
+    {
+        if ($this->getDatasource()->getDbType() === 'pgsql') {
+            // We don't tell PostgreSQL the user's timezone
+            $dateTime = (new DateTime())
+                ->setTimezone(new DateTimeZone('UTC'))
+                ->setTimestamp($value);
+        } else {
+            $dateTime = new DateTime();
+            // Get "current" offset the database will use
+            $offsetToUTC = $dateTime->getOffset();
+            // Set timezone to UTC and initialize it with the timestamp
+            $dateTime->setTimezone(new DateTimeZone('UTC'))->setTimestamp($value);
+            // Normalize every datetime based on the only offset the database knows about
+            if ($offsetToUTC >= 0) {
+                $dateTime->add(new DateInterval("PT{$offsetToUTC}S"));
+            } else {
+                $offsetToUTC = abs($offsetToUTC);
+                $dateTime->sub(new DateInterval("PT{$offsetToUTC}S"));
+            }
+        }
+
+        return $dateTime->format('Y-m-d H:i:s');
+    }
+
+    /**
+     * Check for timestamp fields
+     *
+     * TODO: This is not here to do automagic timestamp stuff. One may
+     *       override this function for custom voodoo, IdoQuery right now
+     *       does. IMO we need to split whereToSql functionality, however
+     *       I'd prefer to wait with this unless we understood how other
+     *       backends will work. We probably should also rename this
+     *       function to isTimestampColumn().
+     *
+     * @param  string $field Field Field name to checked
+     * @return bool          Whether this field expects timestamps
+     */
+    public function isTimestamp($field)
+    {
+        return false;
+    }
+
+    /**
+     * Get the count query
+     *
+     * @return Zend_Db_Select
+     */
+    public function getCountQuery()
+    {
+        // TODO: there may be situations where we should clone the "select"
+        $count = $this->dbSelect();
+        $this->applyFilterSql($count);
+        $group = $this->getGroup();
+        if ($this->useSubqueryCount || $group) {
+            if (! empty($this->columns)) {
+                $count->columns($this->columns);
+            }
+            if ($group) {
+                $count->group($group);
+            }
+            $columns = array('cnt' => 'COUNT(*)');
+            return $this->db->select()->from($count, $columns);
+        }
+
+        $count->columns(array('cnt' => 'COUNT(*)'));
+        return $count;
+    }
+
+    /**
+     * Count all rows of the result set
+     *
+     * @return int
+     */
+    public function count(): int
+    {
+        if ($this->count === null) {
+            $this->count = parent::count();
+        }
+
+        return $this->count;
+    }
+
+    /**
+     * Return the select and count query as a textual representation
+     *
+     * @return string A string containing the select and count query, using unix style newlines as linebreaks
+     */
+    public function dump()
+    {
+        return "QUERY\n=====\n"
+        . $this->getSelectQuery()
+        . "\n\nCOUNT\n=====\n"
+        . $this->getCountQuery()
+        . "\n\n";
+    }
+
+    public function __clone()
+    {
+        parent::__clone();
+        $this->select = clone $this->select;
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString()
+    {
+        try {
+            $select = (string) $this->getSelectQuery();
+            return $this->getIsSubQuery() ? ('(' . $select . ')') : $select;
+        } catch (Exception $e) {
+            Logger::debug('Failed to render DbQuery. An error occured: %s', $e);
+            return '';
+        }
+    }
+
+    /**
+     * Add a GROUP BY clause
+     *
+     * @param   string|array $group
+     *
+     * @return  $this
+     */
+    public function group($group)
+    {
+        $this->group = $group;
+        return $this;
+    }
+
+    /**
+     * Return the GROUP BY clause
+     *
+     * @return  string|array
+     */
+    public function getGroup()
+    {
+        return $this->group;
+    }
+
+    /**
+     * Return whether the given table has been joined
+     *
+     * @param   string  $table
+     *
+     * @return  bool
+     */
+    public function hasJoinedTable($table)
+    {
+        $fromPart = $this->select->getPart(Zend_Db_Select::FROM);
+        if (isset($fromPart[$table])) {
+            return true;
+        }
+
+        foreach ($fromPart as $options) {
+            if ($options['tableName'] === $table && $options['joinType'] !== Zend_Db_Select::FROM) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Return the alias used for joining the given table
+     *
+     * @param   string      $table
+     *
+     * @return  string|null         null in case no alias is being used
+     *
+     * @throws  ProgrammingError    In case the given table has not been joined
+     */
+    public function getJoinedTableAlias($table)
+    {
+        $fromPart = $this->select->getPart(Zend_Db_Select::FROM);
+        if (isset($fromPart[$table])) {
+            if ($fromPart[$table]['joinType'] === Zend_Db_Select::FROM) {
+                throw new ProgrammingError('Table "%s" has not been joined', $table);
+            }
+
+            return; // No alias in use
+        }
+
+        foreach ($fromPart as $alias => $options) {
+            if ($options['tableName'] === $table && $options['joinType'] !== Zend_Db_Select::FROM) {
+                return $alias;
+            }
+        }
+
+        throw new ProgrammingError('Table "%s" has not been joined', $table);
+    }
+
+    /**
+     * Add an INNER JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   string                      $cond   Join on this condition
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function join($name, $cond, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinInner($name, $cond, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add an INNER JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   string                      $cond   Join on this condition
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function joinInner($name, $cond, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinInner($name, $cond, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add a LEFT OUTER JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   string                      $cond   Join on this condition
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function joinLeft($name, $cond, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinLeft($name, $cond, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add a RIGHT OUTER JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   string                      $cond   Join on this condition
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function joinRight($name, $cond, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinRight($name, $cond, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add a FULL OUTER JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   string                      $cond   Join on this condition
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function joinFull($name, $cond, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinFull($name, $cond, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add a CROSS JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function joinCross($name, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinCross($name, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add a NATURAL JOIN table and colums to the query
+     *
+     * @param   array|string|Zend_Db_Expr   $name   The table name
+     * @param   array|string                $cols   The columns to select from the joined table
+     * @param   string                      $schema The database name to specify, if any
+     *
+     * @return  $this
+     */
+    public function joinNatural($name, $cols = Zend_Db_Select::SQL_WILDCARD, $schema = null)
+    {
+        $this->select->joinNatural($name, $cols, $schema);
+        return $this;
+    }
+
+    /**
+     * Add a UNION clause to the query
+     *
+     * @param   array   $select     Select clauses for the union
+     * @param   string  $type       Type of UNION to use
+     *
+     * @return  $this
+     */
+    public function union($select = array(), $type = Zend_Db_Select::SQL_UNION)
+    {
+        $this->select->union($select, $type);
+        return $this;
+    }
+}
diff --git a/library/Icinga/Data/Extensible.php b/library/Icinga/Data/Extensible.php
new file mode 100644
index 0000000..ad690d8
--- /dev/null
+++ b/library/Icinga/Data/Extensible.php
@@ -0,0 +1,22 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Exception\StatementException;
+
+/**
+ * Interface for data insertion
+ */
+interface Extensible
+{
+    /**
+     * Insert the given data for the given target
+     *
+     * @param   string  $target
+     * @param   array   $data
+     *
+     * @throws  StatementException
+     */
+    public function insert($target, array $data);
+}
diff --git a/library/Icinga/Data/Fetchable.php b/library/Icinga/Data/Fetchable.php
new file mode 100644
index 0000000..342740a
--- /dev/null
+++ b/library/Icinga/Data/Fetchable.php
@@ -0,0 +1,47 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * Interface for retrieving data
+ */
+interface Fetchable
+{
+    /**
+     * Retrieve an array containing all rows of the result set
+     *
+     * @return  array
+     */
+    public function fetchAll();
+
+    /**
+     * Fetch the first row of the result set
+     *
+     * @return  mixed
+     */
+    public function fetchRow();
+
+    /**
+     * Fetch the first column of all rows of the result set as an array
+     *
+     * @return  array
+     */
+    public function fetchColumn();
+
+    /**
+     * Fetch the first column of the first row of the result set
+     *
+     * @return  string
+     */
+    public function fetchOne();
+
+    /**
+     * Fetch all rows of the result set as an array of key-value pairs
+     *
+     * The first column is the key, the second column is the value.
+     *
+     * @return  array
+     */
+    public function fetchPairs();
+}
diff --git a/library/Icinga/Data/Filter/Filter.php b/library/Icinga/Data/Filter/Filter.php
new file mode 100644
index 0000000..f5d8bdf
--- /dev/null
+++ b/library/Icinga/Data/Filter/Filter.php
@@ -0,0 +1,255 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+use Icinga\Web\UrlParams;
+use Icinga\Exception\ProgrammingError;
+
+/**
+ * Filter
+ *
+ * Base class for filters (why?) and factory for the different FilterOperators
+ */
+abstract class Filter
+{
+    protected $id = '1';
+
+    public function setId($id)
+    {
+        $this->id = (string) $id;
+        return $this;
+    }
+
+    abstract public function isExpression();
+
+    abstract public function isChain();
+
+    abstract public function isEmpty();
+
+    abstract public function toQueryString();
+
+    abstract public function andFilter(Filter $filter);
+
+    abstract public function orFilter(Filter $filter);
+
+    /**
+     * Whether the give row matches this Filter
+     *
+     * @param mixed $row Preferrably an stdClass instance
+     * @return bool
+     */
+    abstract public function matches($row);
+
+    public function getUrlParams()
+    {
+        return UrlParams::fromQueryString($this->toQueryString());
+    }
+
+    public function getById($id)
+    {
+        if ((string) $id === $this->getId()) {
+            return $this;
+        }
+        throw new ProgrammingError(
+            'Trying to get invalid filter index "%s" from "%s" ("%s")',
+            $id,
+            $this,
+            $this->id
+        );
+    }
+
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    public function isRootNode()
+    {
+        return false === strpos($this->id, '-');
+    }
+
+    abstract public function listFilteredColumns();
+
+    public function applyChanges($changes)
+    {
+        $filter = $this;
+        $pairs = array();
+        foreach ($changes as $k => $v) {
+            if (preg_match('/^(column|value|sign|operator)_([\d-]+)$/', $k, $m)) {
+                $pairs[$m[2]][$m[1]] = $v;
+            }
+        }
+        $operators = array();
+        foreach ($pairs as $id => $fs) {
+            if (array_key_exists('operator', $fs)) {
+                $operators[$id] = $fs['operator'];
+            } else {
+                $f = $filter->getById($id);
+                $f->setColumn($fs['column']);
+                if ($f->getSign() !== $fs['sign']) {
+                    if ($f->isRootNode()) {
+                        $filter = $f->setSign($fs['sign']);
+                    } else {
+                        $filter->replaceById($id, $f->setSign($fs['sign']));
+                    }
+                }
+                $f->setExpression($fs['value']);
+            }
+        }
+
+        krsort($operators, SORT_NATURAL);
+        foreach ($operators as $id => $operator) {
+            $f = $filter->getById($id);
+            if ($f->getOperatorName() !== $operator) {
+                if ($f->isRootNode()) {
+                    $filter = $f->setOperatorName($operator);
+                } else {
+                    $filter->replaceById($id, $f->setOperatorName($operator));
+                }
+            }
+        }
+
+        return $filter;
+    }
+
+    public function getParentId()
+    {
+        if ($this->isRootNode()) {
+            throw new ProgrammingError('Filter root nodes have no parent');
+        }
+        return substr($this->id, 0, strrpos($this->id, '-'));
+    }
+
+    public function getParent()
+    {
+        return $this->getById($this->getParentId());
+    }
+
+    public function hasId($id)
+    {
+        if ($id === $this->getId()) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Where Filter factory
+     *
+     * @param string $col     Column to be filtered
+     * @param string $filter  Filter expression
+     *
+     * @throws FilterException
+     * @return FilterExpression
+     */
+    public static function where($col, $filter)
+    {
+        return new FilterExpression($col, '=', $filter);
+    }
+
+    public static function expression($col, $op, $expression)
+    {
+        switch ($op) {
+            case '=':
+                return new FilterMatch($col, $op, $expression);
+            case '<':
+                return new FilterLessThan($col, $op, $expression);
+            case '>':
+                return new FilterGreaterThan($col, $op, $expression);
+            case '>=':
+                return new FilterEqualOrGreaterThan($col, $op, $expression);
+            case '<=':
+                return new FilterEqualOrLessThan($col, $op, $expression);
+            case '!=':
+                return new FilterMatchNot($col, $op, $expression);
+            default:
+                throw new ProgrammingError(
+                    'There is no such filter sign: %s',
+                    $op
+                );
+        }
+    }
+
+    /**
+     * Or FilterOperator factory
+     *
+     * @param Filter $filter,...  Unlimited optional list of Filters
+     *
+     * @return FilterOr
+     */
+    public static function matchAny()
+    {
+        $args = func_get_args();
+        if (count($args) === 1 && is_array($args[0])) {
+            $args = $args[0];
+        }
+        return new FilterOr($args);
+    }
+
+    /**
+     * Or FilterOperator factory
+     *
+     * @param Filter $filter,...  Unlimited optional list of Filters
+     *
+     * @return FilterAnd
+     */
+    public static function matchAll()
+    {
+        $args = func_get_args();
+        if (count($args) === 1 && is_array($args[0])) {
+            $args = $args[0];
+        }
+        return new FilterAnd($args);
+    }
+
+    /**
+     * FilterNot factory, negates the given filter
+     *
+     * @param Filter $filter Filter to be negated
+     *
+     * @return FilterNot
+     */
+    public static function not()
+    {
+        $args = func_get_args();
+        if (count($args) === 1) {
+            if (is_array($args[0])) {
+                $args = $args[0];
+            }
+        }
+        if (count($args) > 1) {
+            return new FilterNot(array(new FilterAnd($args)));
+        } else {
+            return new FilterNot($args);
+        }
+    }
+
+    public static function chain($operator, $filters = array())
+    {
+        switch ($operator) {
+            case 'AND':
+                return self::matchAll($filters);
+            case 'OR':
+                return self::matchAny($filters);
+            case 'NOT':
+                return self::not($filters);
+        }
+        throw new ProgrammingError(
+            '"%s" is not a valid filter chain operator',
+            $operator
+        );
+    }
+
+    /**
+     * Create filter from queryString
+     *
+     * This is still pretty basic, need improvement
+     *
+     * @return static
+     */
+    public static function fromQueryString($query)
+    {
+        return FilterQueryString::parse($query);
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterAnd.php b/library/Icinga/Data/Filter/FilterAnd.php
new file mode 100644
index 0000000..96b68cc
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterAnd.php
@@ -0,0 +1,42 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+/**
+ * Filter list AND
+ *
+ * Binary AND, all contained filters must succeed
+ */
+class FilterAnd extends FilterChain
+{
+    protected $operatorName = 'AND';
+
+    protected $operatorSymbol = '&';
+
+    /**
+     * Whether the given row object matches this filter
+     *
+     * @object $row
+     * @return boolean
+     */
+    public function matches($row)
+    {
+        foreach ($this->filters as $filter) {
+            if (! $filter->matches($row)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public function andFilter(Filter $filter)
+    {
+        return $this->addFilter($filter);
+    }
+
+    public function orFilter(Filter $filter)
+    {
+        return Filter::matchAny($this, $filter);
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterChain.php b/library/Icinga/Data/Filter/FilterChain.php
new file mode 100644
index 0000000..0f1e071
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterChain.php
@@ -0,0 +1,286 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+use Icinga\Exception\ProgrammingError;
+use Icinga\Exception\QueryException;
+
+/**
+ * FilterChain
+ *
+ * A FilterChain contains a list ...
+ */
+abstract class FilterChain extends Filter
+{
+    protected $filters = array();
+
+    protected $operatorName;
+
+    protected $operatorSymbol;
+
+    protected $allowedColumns;
+
+    /**
+     * Set the filters
+     *
+     * @param   array   $filters
+     *
+     * @return  $this
+     */
+    public function setFilters(array $filters)
+    {
+        $this->filters = $filters;
+
+        $this->refreshChildIds();
+
+        return $this;
+    }
+
+    public function hasId($id)
+    {
+        foreach ($this->filters() as $filter) {
+            if ($filter->hasId($id)) {
+                return true;
+            }
+        }
+        return parent::hasId($id);
+    }
+
+    public function getById($id)
+    {
+        foreach ($this->filters() as $filter) {
+            if ($filter->hasId($id)) {
+                return $filter->getById($id);
+            }
+        }
+        return parent::getById($id);
+    }
+
+    public function removeId($id)
+    {
+        if ($id === $this->getId()) {
+            $this->filters = array();
+            return $this;
+        }
+        $remove = null;
+        foreach ($this->filters as $key => $filter) {
+            if ($filter->getId() === $id) {
+                $remove = $key;
+            } elseif ($filter instanceof FilterChain) {
+                $filter->removeId($id);
+            }
+        }
+        if ($remove !== null) {
+            unset($this->filters[$remove]);
+            $this->filters = array_values($this->filters);
+        }
+        $this->refreshChildIds();
+        return $this;
+    }
+
+    public function replaceById($id, $filter)
+    {
+        $found = false;
+        foreach ($this->filters as $k => $child) {
+            if ($child->getId() == $id) {
+                $this->filters[$k] = $filter;
+                $found = true;
+                break;
+            }
+            if ($child->hasId($id)) {
+                $child->replaceById($id, $filter);
+                $found = true;
+                break;
+            }
+        }
+        if (! $found) {
+            throw new ProgrammingError('You tried to replace an unexistant child filter');
+        }
+        $this->refreshChildIds();
+        return $this;
+    }
+
+    protected function refreshChildIds()
+    {
+        $i = 0;
+        $id = $this->getId();
+        foreach ($this->filters as $filter) {
+            $i++;
+            $filter->setId($id . '-' . $i);
+        }
+        return $this;
+    }
+
+    public function setId($id)
+    {
+        return parent::setId($id)->refreshChildIds();
+    }
+
+    public function getOperatorName()
+    {
+        return $this->operatorName;
+    }
+
+    public function setOperatorName($name)
+    {
+        if ($name !== $this->operatorName) {
+            return Filter::chain($name, $this->filters);
+        }
+        return $this;
+    }
+
+    public function getOperatorSymbol()
+    {
+        return $this->operatorSymbol;
+    }
+
+    public function setAllowedFilterColumns(array $columns)
+    {
+        $this->allowedColumns = $columns;
+        return $this;
+    }
+
+    /**
+     * List and return all column names referenced in this filter
+     *
+     * @param   array   $columns    The columns listed so far
+     *
+     * @return  array
+     */
+    public function listFilteredColumns(array $columns = array())
+    {
+        foreach ($this->filters as $filter) {
+            if ($filter instanceof FilterExpression) {
+                $column= $filter->getColumn();
+                if (! in_array($column, $columns, true)) {
+                    $columns[] = $column;
+                }
+            } else {
+                $columns = $filter->listFilteredColumns($columns);
+            }
+        }
+
+        return $columns;
+    }
+
+    public function toQueryString()
+    {
+        $parts = array();
+        if (empty($this->filters)) {
+            return '';
+        }
+        foreach ($this->filters() as $filter) {
+            if (! $filter->isEmpty()) {
+                $parts[] = $filter->toQueryString();
+            }
+        }
+
+        // TODO: getLevel??
+        if (strpos($this->getId(), '-')) {
+            return '(' . implode($this->getOperatorSymbol(), $parts) . ')';
+        } else {
+            return implode($this->getOperatorSymbol(), $parts);
+        }
+    }
+
+    /**
+     * Get simple string representation
+     *
+     * Useful for debugging only
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        if (empty($this->filters)) {
+            return '';
+        }
+        $parts = array();
+        foreach ($this->filters as $filter) {
+            if ($filter instanceof FilterChain) {
+                $parts[] = '(' . $filter . ')';
+            } else {
+                $parts[] = (string) $filter;
+            }
+        }
+        $op = ' '  . $this->getOperatorSymbol() . ' ';
+        return implode($op, $parts);
+    }
+
+    public function __construct($filters = array())
+    {
+        foreach ($filters as $filter) {
+            $this->addFilter($filter);
+        }
+    }
+
+    public function isExpression()
+    {
+        return false;
+    }
+
+    public function isChain()
+    {
+        return true;
+    }
+
+    public function isEmpty()
+    {
+        return empty($this->filters);
+    }
+
+    public function addFilter(Filter $filter)
+    {
+        if (! empty($this->allowedColumns)) {
+            $this->validateFilterColumns($filter);
+        }
+
+        $this->filters[] = $filter;
+        $filter->setId($this->getId() . '-' . $this->count());
+        return $this;
+    }
+
+    protected function validateFilterColumns(Filter $filter)
+    {
+        if ($filter->isExpression()) {
+            $valid = false;
+            foreach ($this->allowedColumns as $column) {
+                if (is_callable($column)) {
+                    if (call_user_func($column, $filter->getColumn())) {
+                        $valid = true;
+                        break;
+                    }
+                } elseif ($filter->getColumn() === $column) {
+                    $valid = true;
+                    break;
+                }
+            }
+
+            if (! $valid) {
+                throw new QueryException('Invalid filter column provided: %s', $filter->getColumn());
+            }
+        } else {
+            foreach ($filter->filters() as $subFilter) {
+                $this->validateFilterColumns($subFilter);
+            }
+        }
+    }
+
+    public function &filters()
+    {
+        return $this->filters;
+    }
+
+    public function count()
+    {
+        return count($this->filters);
+    }
+
+    public function __clone()
+    {
+        foreach ($this->filters as & $filter) {
+            $filter = clone $filter;
+        }
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterEqual.php b/library/Icinga/Data/Filter/FilterEqual.php
new file mode 100644
index 0000000..da53d3f
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterEqual.php
@@ -0,0 +1,16 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterEqual extends FilterExpression
+{
+    public function matches($row)
+    {
+        if (! isset($row->{$this->column})) {
+            return false;
+        }
+
+        return (string) $row->{$this->column} === (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterEqualOrGreaterThan.php b/library/Icinga/Data/Filter/FilterEqualOrGreaterThan.php
new file mode 100644
index 0000000..d7bd5b8
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterEqualOrGreaterThan.php
@@ -0,0 +1,16 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterEqualOrGreaterThan extends FilterExpression
+{
+    public function matches($row)
+    {
+        if (! isset($row->{$this->column})) {
+            return false;
+        }
+
+        return (string) $row->{$this->column} >= (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterEqualOrLessThan.php b/library/Icinga/Data/Filter/FilterEqualOrLessThan.php
new file mode 100644
index 0000000..8016fc4
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterEqualOrLessThan.php
@@ -0,0 +1,26 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterEqualOrLessThan extends FilterExpression
+{
+    public function __toString()
+    {
+        return $this->column . ' <= ' . $this->expression;
+    }
+
+    public function toQueryString()
+    {
+        return $this->column . '<=' . $this->expression;
+    }
+
+    public function matches($row)
+    {
+        if (! isset($row->{$this->column})) {
+            return false;
+        }
+
+        return (string) $row->{$this->column} <= (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterException.php b/library/Icinga/Data/Filter/FilterException.php
new file mode 100644
index 0000000..842d7ab
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterException.php
@@ -0,0 +1,15 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+use Icinga\Exception\IcingaException;
+
+/**
+ * Filter Exception Class
+ *
+ * Filter Exceptions should be thrown on filter parse errors or similar
+ */
+class FilterException extends IcingaException
+{
+}
diff --git a/library/Icinga/Data/Filter/FilterExpression.php b/library/Icinga/Data/Filter/FilterExpression.php
new file mode 100644
index 0000000..73fb625
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterExpression.php
@@ -0,0 +1,224 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+use Exception;
+
+class FilterExpression extends Filter
+{
+    protected $column;
+    protected $sign;
+    protected $expression;
+
+    /**
+     * Does this filter compare case sensitive?
+     *
+     * @var bool
+     */
+    protected $caseSensitive;
+
+    public function __construct($column, $sign, $expression)
+    {
+        $column = trim($column);
+        $this->column = $column;
+        $this->sign = $sign;
+        $this->expression = $expression;
+        $this->caseSensitive = true;
+    }
+
+    public function isExpression()
+    {
+        return true;
+    }
+
+    public function isChain()
+    {
+        return false;
+    }
+
+    public function isEmpty()
+    {
+        return false;
+    }
+
+    public function getColumn()
+    {
+        return $this->column;
+    }
+
+    public function getSign()
+    {
+        return $this->sign;
+    }
+
+    public function setColumn($column)
+    {
+        $this->column = $column;
+        return $this;
+    }
+
+    public function getExpression()
+    {
+        return $this->expression;
+    }
+
+    /**
+     * Return whether this filter compares case sensitive
+     *
+     * @return bool
+     */
+    public function getCaseSensitive()
+    {
+        return $this->caseSensitive;
+    }
+
+    public function setExpression($expression)
+    {
+        $this->expression = $expression;
+        return $this;
+    }
+
+    public function setSign($sign)
+    {
+        if ($sign !== $this->sign) {
+            return Filter::expression($this->column, $sign, $this->expression);
+        }
+        return $this;
+    }
+
+    /**
+     * Set this filter's case sensitivity
+     *
+     * @param   bool    $caseSensitive
+     *
+     * @return $this
+     */
+    public function setCaseSensitive($caseSensitive = true)
+    {
+        $this->caseSensitive = $caseSensitive;
+        return $this;
+    }
+
+    public function listFilteredColumns()
+    {
+        return array($this->getColumn());
+    }
+
+    public function __toString()
+    {
+        if ($this->isBooleanTrue()) {
+            return $this->column;
+        }
+
+        $expression = is_array($this->expression) ?
+             '( ' . implode(' | ', $this->expression) . ' )' :
+             $this->expression;
+
+        return sprintf(
+            '%s %s %s',
+            $this->column,
+            $this->sign,
+            $expression
+        );
+    }
+
+    public function toQueryString()
+    {
+        if ($this->isBooleanTrue()) {
+            return $this->column;
+        }
+
+        $expression = is_array($this->expression) ?
+             '(' . implode('|', array_map('rawurlencode', $this->expression)) . ')' :
+             rawurlencode($this->expression);
+
+        return $this->column . $this->sign . $expression;
+    }
+
+    protected function isBooleanTrue()
+    {
+        return $this->sign === '=' && $this->expression === true;
+    }
+
+    /**
+     * If $var is a scalar, do the same as strtolower() would do.
+     * If $var is an array, map $this->strtolowerRecursive() to its elements.
+     * Otherwise, return $var unchanged.
+     *
+     * @param   mixed   $var
+     *
+     * @return  mixed
+     */
+    protected function strtolowerRecursive($var)
+    {
+        if ($var === null) {
+            return '';
+        }
+        if (is_scalar($var)) {
+            return strtolower($var);
+        }
+        if (is_array($var)) {
+            return array_map(array($this, 'strtolowerRecursive'), $var);
+        }
+        return $var;
+    }
+
+    public function matches($row)
+    {
+        try {
+            $rowValue = $row->{$this->column};
+        } catch (Exception $e) {
+            // TODO: REALLY? Exception?
+            return false;
+        }
+
+        if ($this->caseSensitive) {
+            $expression = $this->expression;
+        } else {
+            $rowValue = $this->strtolowerRecursive($rowValue);
+            $expression = $this->strtolowerRecursive($this->expression);
+        }
+
+        if (is_array($expression)) {
+            return in_array($rowValue, $expression);
+        }
+
+        $expression = (string) $expression;
+        if (strpos($expression, '*') === false) {
+            if (is_array($rowValue)) {
+                return in_array($expression, $rowValue);
+            }
+
+            return (string) $rowValue === $expression;
+        }
+
+        $parts = array();
+        foreach (preg_split('~\*~', $expression) as $part) {
+            $parts[] = preg_quote($part, '/');
+        }
+        $pattern = '/^' . implode('.*', $parts) . '$/';
+
+        if (is_array($rowValue)) {
+            foreach ($rowValue as $candidate) {
+                if (preg_match($pattern, $candidate)) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        return $rowValue !== null && preg_match($pattern, $rowValue);
+    }
+
+    public function andFilter(Filter $filter)
+    {
+        return Filter::matchAll($this, $filter);
+    }
+
+    public function orFilter(Filter $filter)
+    {
+        return Filter::matchAny($this, $filter);
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterGreaterThan.php b/library/Icinga/Data/Filter/FilterGreaterThan.php
new file mode 100644
index 0000000..92a0e62
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterGreaterThan.php
@@ -0,0 +1,16 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterGreaterThan extends FilterExpression
+{
+    public function matches($row)
+    {
+        if (! isset($row->{$this->column})) {
+            // TODO: REALLY? Exception?
+            return false;
+        }
+        return (string) $row->{$this->column} > (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterLessThan.php b/library/Icinga/Data/Filter/FilterLessThan.php
new file mode 100644
index 0000000..c13a1ce
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterLessThan.php
@@ -0,0 +1,26 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterLessThan extends FilterExpression
+{
+    public function __toString()
+    {
+        return $this->column . ' < ' . $this->expression;
+    }
+
+    public function toQueryString()
+    {
+        return $this->column . '<' . $this->expression;
+    }
+
+    public function matches($row)
+    {
+        if (! isset($row->{$this->column})) {
+            return false;
+        }
+
+        return (string) $row->{$this->column} < (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterMatch.php b/library/Icinga/Data/Filter/FilterMatch.php
new file mode 100644
index 0000000..a3befad
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterMatch.php
@@ -0,0 +1,8 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterMatch extends FilterExpression
+{
+}
diff --git a/library/Icinga/Data/Filter/FilterMatchCaseInsensitive.php b/library/Icinga/Data/Filter/FilterMatchCaseInsensitive.php
new file mode 100644
index 0000000..9eca173
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterMatchCaseInsensitive.php
@@ -0,0 +1,13 @@
+<?php
+/* Icinga Web 2 | (c) 2016 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterMatchCaseInsensitive extends FilterMatch
+{
+    public function __construct($column, $sign, $expression)
+    {
+        parent::__construct($column, $sign, $expression);
+        $this->caseSensitive = false;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterMatchNot.php b/library/Icinga/Data/Filter/FilterMatchNot.php
new file mode 100644
index 0000000..1e5050e
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterMatchNot.php
@@ -0,0 +1,12 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterMatchNot extends FilterExpression
+{
+    public function matches($row)
+    {
+        return !parent::matches($row);
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterMatchNotCaseInsensitive.php b/library/Icinga/Data/Filter/FilterMatchNotCaseInsensitive.php
new file mode 100644
index 0000000..3838fa2
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterMatchNotCaseInsensitive.php
@@ -0,0 +1,13 @@
+<?php
+/* Icinga Web 2 | (c) 2016 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterMatchNotCaseInsensitive extends FilterMatchNot
+{
+    public function __construct($column, $sign, $expression)
+    {
+        parent::__construct($column, $sign, $expression);
+        $this->caseSensitive = false;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterNot.php b/library/Icinga/Data/Filter/FilterNot.php
new file mode 100644
index 0000000..b61f497
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterNot.php
@@ -0,0 +1,58 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterNot extends FilterChain
+{
+    protected $operatorName = 'NOT';
+
+    protected $operatorSymbol = '!'; // BULLSHIT
+
+// TODO: Max count 1 or autocreate sub-and?
+
+    public function matches($row)
+    {
+        foreach ($this->filters() as $filter) {
+            if ($filter->matches($row)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public function andFilter(Filter $filter)
+    {
+        return Filter::matchAll($this, $filter);
+    }
+
+    public function orFilter(Filter $filter)
+    {
+        return Filter::matchAny($filter);
+    }
+
+    public function toQueryString()
+    {
+        $parts = array();
+        if (empty($this->filters)) {
+            return '';
+        }
+
+        foreach ($this->filters() as $filter) {
+            $parts[] = $filter->toQueryString();
+        }
+        if (count($parts) === 1) {
+            return '!' . $parts[0];
+        } else {
+            return '!(' . implode('&', $parts) . ')';
+        }
+    }
+
+    public function __toString()
+    {
+        if (count($this->filters) === 1) {
+            return '! ' . $this->filters[0];
+        }
+        return '! (' . implode('&', $this->filters) . ')';
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterNotEqual.php b/library/Icinga/Data/Filter/FilterNotEqual.php
new file mode 100644
index 0000000..8915a3d
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterNotEqual.php
@@ -0,0 +1,12 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterNotEqual extends FilterExpression
+{
+    public function matches($row)
+    {
+        return (string) $row->{$this->column} !== (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterOr.php b/library/Icinga/Data/Filter/FilterOr.php
new file mode 100644
index 0000000..aca91f3
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterOr.php
@@ -0,0 +1,39 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterOr extends FilterChain
+{
+    protected $operatorName = 'OR';
+
+    protected $operatorSymbol = '|';
+
+    public function matches($row)
+    {
+        foreach ($this->filters as $filter) {
+            if ($filter->matches($row)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public function setOperatorName($name)
+    {
+        if ($this->count() > 1 && $name === 'NOT') {
+            return Filter::not(clone $this);
+        }
+        return parent::setOperatorName($name);
+    }
+
+    public function andFilter(Filter $filter)
+    {
+        return Filter::matchAll($this, $filter);
+    }
+
+    public function orFilter(Filter $filter)
+    {
+        return $this->addFilter($filter);
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterParseException.php b/library/Icinga/Data/Filter/FilterParseException.php
new file mode 100644
index 0000000..f2b732b
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterParseException.php
@@ -0,0 +1,10 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+use Icinga\Exception\IcingaException;
+
+class FilterParseException extends IcingaException
+{
+}
diff --git a/library/Icinga/Data/Filter/FilterQueryString.php b/library/Icinga/Data/Filter/FilterQueryString.php
new file mode 100644
index 0000000..8535df5
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterQueryString.php
@@ -0,0 +1,320 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Filter;
+
+class FilterQueryString
+{
+    protected $string;
+
+    protected $pos;
+
+    protected $debug = array();
+
+    protected $reportDebug = false;
+
+    protected $length;
+
+    protected function __construct()
+    {
+    }
+
+    protected function debug($msg, $level = 0, $op = null)
+    {
+        if ($op === null) {
+            $op = 'NULL';
+        }
+        $this->debug[] = sprintf(
+            '%s[%d=%s] (%s): %s',
+            str_repeat('* ', $level),
+            $this->pos,
+            $this->string[$this->pos - 1],
+            $op,
+            $msg
+        );
+    }
+
+    public static function parse($string)
+    {
+        $parser = new static();
+        return $parser->parseQueryString($string);
+    }
+
+    protected function readNextKey()
+    {
+        $str = $this->readUnlessSpecialChar();
+
+        if ($str === false) {
+            return $str;
+        }
+        return rawurldecode($str);
+    }
+
+    protected function readNextValue()
+    {
+        if ($this->nextChar() === '(') {
+            $this->readChar();
+            $var = preg_split('~\|~', $this->readUnless(')'));
+            if ($this->readChar() !== ')') {
+                $this->parseError(null, 'Expected ")"');
+            }
+        } else {
+            $var = rawurldecode($this->readUnless(array(')', '&', '|', '>', '<')));
+        }
+        return $var;
+    }
+
+    protected function readNextExpression()
+    {
+        if ('' === ($key = $this->readNextKey())) {
+            return false;
+        }
+
+        foreach (array('<', '>') as $sign) {
+            if (false !== ($pos = strpos($key, $sign))) {
+                if ($this->nextChar() === '=') {
+                    break;
+                }
+                $var = substr($key, $pos + 1);
+                $key = substr($key, 0, $pos);
+
+                if (ctype_digit($var)) {
+                    $var = (float) $var;
+                }
+
+                return Filter::expression($key, $sign, $var);
+            }
+        }
+        if (in_array($this->nextChar(), array('=', '>', '<', '!'))) {
+            $sign = $this->readChar();
+        } else {
+            $sign = false;
+        }
+        if ($sign === false) {
+            return Filter::expression($key, '=', true);
+        }
+
+        $toFloat = false;
+        if ($sign === '=') {
+            $last = substr($key, -1);
+            if ($last === '>' || $last === '<') {
+                $sign = $last . $sign;
+                $key = substr($key, 0, -1);
+                $toFloat = true;
+            }
+        // TODO: Same as above for unescaped <> - do we really need this?
+        } elseif ($sign === '>' || $sign === '<' || $sign === '!') {
+            $toFloat = $sign === '>' || $sign === '<';
+            if ($this->nextChar() === '=') {
+                $sign .= $this->readChar();
+            }
+        }
+
+        $var = $this->readNextValue();
+        if ($toFloat && ctype_digit($var)) {
+            $var = (float) $var;
+        }
+
+        return Filter::expression($key, $sign, $var);
+    }
+
+    protected function parseError($char = null, $extraMsg = null)
+    {
+        if ($extraMsg === null) {
+            $extra = '';
+        } else {
+            $extra = ': ' . $extraMsg;
+        }
+        if ($char === null) {
+            $char = $this->string[$this->pos];
+        }
+        if ($this->reportDebug) {
+            $extra .= "\n" . implode("\n", $this->debug);
+        }
+
+        throw new FilterParseException(
+            'Invalid filter "%s", unexpected %s at pos %d%s',
+            $this->string,
+            $char,
+            $this->pos,
+            $extra
+        );
+    }
+
+    protected function readFilters($nestingLevel = 0, $op = null)
+    {
+        $filters = array();
+        while ($this->pos < $this->length) {
+            if ($op === '!' && count($filters) === 1) {
+                break;
+            }
+            $filter = $this->readNextExpression();
+            $next = $this->readChar();
+
+
+            if ($filter === false) {
+                $this->debug('Got no next expression, next is ' . $next, $nestingLevel, $op);
+                if ($next === '!') {
+                    $not = $this->readFilters($nestingLevel + 1, '!');
+                    $filters[] = $not;
+                    if (in_array($this->nextChar(), array('|', '&', ')'))) {
+                        $next = $this->readChar();
+                        $this->debug('Got NOT, next is now: ' . $next, $nestingLevel, $op);
+                    } else {
+                        $this->debug('Breaking after NOT: ' . $not, $nestingLevel, $op);
+                        break;
+                    }
+                }
+
+                if ($op === null && count($filters) > 0 && ($next === '&' || $next === '|')) {
+                    $op = $next;
+                    continue;
+                }
+
+                if ($next === false) {
+                    // Nothing more to read
+                    break;
+                }
+
+                if ($next === ')') {
+                    if ($nestingLevel > 0) {
+                        $this->debug('Closing without filter: ' . $next, $nestingLevel, $op);
+                        break;
+                    }
+                    $this->parseError($next);
+                }
+                if ($next === '(') {
+                    $filters[] = $this->readFilters($nestingLevel + 1, null);
+                    continue;
+                }
+                if ($next === $op) {
+                    continue;
+                }
+                $this->parseError($next, "$op level $nestingLevel");
+            } else {
+                $this->debug('Got new expression: ' . $filter, $nestingLevel, $op);
+
+                $filters[] = $filter;
+
+                if ($next === false) {
+                    $this->debug('Next is false, nothing to read but got filter', $nestingLevel, $op);
+                    // Got filter, nothing more to read
+                    break;
+                }
+
+                if ($op === '!') {
+                    $this->pos--;
+                    break;
+                }
+                if ($next === $op) {
+                    $this->debug('Next matches operator', $nestingLevel, $op);
+                    continue; // Break??
+                }
+
+                if ($next === ')') {
+                    if ($nestingLevel > 0) {
+                        $this->debug('Closing with filter: ' . $next, $nestingLevel, $op);
+                        break;
+                    }
+                    $this->parseError($next);
+                }
+                if ($op === null && in_array($next, array('&', '|'))) {
+                    $this->debug('Setting op to ' . $next, $nestingLevel, $op);
+                    $op = $next;
+                    continue;
+                }
+                $this->parseError($next);
+            }
+        }
+
+        if ($nestingLevel === 0 && $this->pos < $this->length) {
+            $this->parseError($op, 'Did not read full filter');
+        }
+
+        if ($nestingLevel === 0 && count($filters) === 1 && $op !== '!') {
+            // There is only one filter expression, no chain
+            $this->debug('Returning first filter only: ' . $filters[0], $nestingLevel, $op);
+            return $filters[0];
+        }
+
+        if ($op === null && count($filters) === 1) {
+            $this->debug('No op, single filter, setting AND', $nestingLevel, $op);
+            $op = '&';
+        }
+        $this->debug(sprintf('Got %d filters, returning', count($filters)), $nestingLevel, $op);
+
+        switch ($op) {
+            case '&':
+                return Filter::matchAll($filters);
+            case '|':
+                return Filter::matchAny($filters);
+            case '!':
+                return Filter::not($filters);
+            case null:
+                return Filter::matchAll();
+            default:
+                $this->parseError($op);
+        }
+    }
+
+    protected function parseQueryString($string)
+    {
+        $this->pos = 0;
+
+        $this->string = $string;
+
+        $this->length = $string ? strlen($string) : 0;
+
+        if ($this->length === 0) {
+            return Filter::matchAll();
+        }
+        return $this->readFilters();
+    }
+
+    protected function readUnless($char)
+    {
+        $buffer = '';
+        while (false !== ($c = $this->readChar())) {
+            if (is_array($char)) {
+                if (in_array($c, $char)) {
+                    $this->pos--;
+                    break;
+                }
+            } else {
+                if ($c === $char) {
+                    $this->pos--;
+                    break;
+                }
+            }
+            $buffer .= $c;
+        }
+
+        return $buffer;
+    }
+
+    protected function readUnlessSpecialChar()
+    {
+        return $this->readUnless(array('=', '(', ')', '&', '|', '>', '<', '!'));
+    }
+
+    protected function readExpressionOperator()
+    {
+        return $this->readUnless(array('=', '>', '<', '!'));
+    }
+
+    protected function readChar()
+    {
+        if ($this->length > $this->pos) {
+            return $this->string[$this->pos++];
+        }
+        return false;
+    }
+
+    protected function nextChar()
+    {
+        if ($this->length > $this->pos) {
+            return $this->string[$this->pos];
+        }
+        return false;
+    }
+}
diff --git a/library/Icinga/Data/FilterColumns.php b/library/Icinga/Data/FilterColumns.php
new file mode 100644
index 0000000..7eaacea
--- /dev/null
+++ b/library/Icinga/Data/FilterColumns.php
@@ -0,0 +1,21 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+interface FilterColumns
+{
+    /**
+     * Return a filterable's filter columns with their optional label as key
+     *
+     * @return  array
+     */
+    public function getFilterColumns();
+
+    /**
+     * Return a filterable's search columns
+     *
+     * @return  array
+     */
+    public function getSearchColumns();
+}
diff --git a/library/Icinga/Data/Filterable.php b/library/Icinga/Data/Filterable.php
new file mode 100644
index 0000000..ceca22f
--- /dev/null
+++ b/library/Icinga/Data/Filterable.php
@@ -0,0 +1,27 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Data\Filter\Filter;
+
+/**
+ * Interface for filtering a result set
+ *
+ * @deprecated(EL): addFilter and applyFilter do the same in all usages.
+ * addFilter could be replaced w/ getFilter()->add(). We must no require classes implementing this interface to
+ * implement redundant methods over and over again. This interface must be moved to the namespace Icinga\Data\Filter.
+ * It lacks documentation.
+ */
+interface Filterable
+{
+    public function applyFilter(Filter $filter);
+
+    public function setFilter(Filter $filter);
+
+    public function getFilter();
+
+    public function addFilter(Filter $filter);
+
+    public function where($condition, $value = null);
+}
diff --git a/library/Icinga/Data/Identifiable.php b/library/Icinga/Data/Identifiable.php
new file mode 100644
index 0000000..7435026
--- /dev/null
+++ b/library/Icinga/Data/Identifiable.php
@@ -0,0 +1,17 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * Interface for objects that are identifiable by an ID of any type
+ */
+interface Identifiable
+{
+    /**
+     * Get the ID associated with this Identifiable object
+     *
+     * @return mixed
+     */
+    public function getId();
+}
diff --git a/library/Icinga/Data/Inspectable.php b/library/Icinga/Data/Inspectable.php
new file mode 100644
index 0000000..d40ce57
--- /dev/null
+++ b/library/Icinga/Data/Inspectable.php
@@ -0,0 +1,20 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * An object for which the user can retrieve status information
+ *
+ * This interface is useful for providing summaries or diagnostic information about objects
+ * to users.
+ */
+interface Inspectable
+{
+    /**
+     * Inspect this object to gain extended information about its health
+     *
+     * @return Inspection           The inspection result
+     */
+    public function inspect();
+}
diff --git a/library/Icinga/Data/Inspection.php b/library/Icinga/Data/Inspection.php
new file mode 100644
index 0000000..b0dd298
--- /dev/null
+++ b/library/Icinga/Data/Inspection.php
@@ -0,0 +1,129 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Application\Logger;
+use Icinga\Exception\ProgrammingError;
+
+/**
+ * Contains information about an object in the form of human-readable log entries and indicates if the object has errors
+ */
+class Inspection
+{
+    /**
+     * @var array
+     */
+    protected $log = array();
+
+    /**
+     * @var string
+     */
+    protected $description;
+
+    /**
+     * @var string|Inspection
+     */
+    protected $error;
+
+    /**
+     * @param $description     Describes the object that is being inspected
+     */
+    public function __construct($description)
+    {
+        $this->description = $description;
+    }
+
+    /**
+     * Get the name of this Inspection
+     *
+     * @return mixed
+     */
+    public function getDescription()
+    {
+        return $this->description;
+    }
+
+    /**
+     * Append the given log entry or nested inspection
+     *
+     * @throws  ProgrammingError            When called after erroring
+     *
+     * @param $entry    string|Inspection   A log entry or nested inspection
+     */
+    public function write($entry)
+    {
+        if (isset($this->error)) {
+            throw new ProgrammingError('Inspection object used after error');
+        }
+        if ($entry instanceof Inspection) {
+            $this->log[$entry->description] = $entry->toArray();
+        } else {
+            Logger::debug($entry);
+            $this->log[] = $entry;
+        }
+    }
+
+    /**
+     * Append the given log entry and fail this inspection with the given error
+     *
+     * @param   $entry  string|Inspection   A log entry or nested inspection
+     *
+     * @throws  ProgrammingError            When called multiple times
+     *
+     * @return  $this                        fluent interface
+     */
+    public function error($entry)
+    {
+        if (isset($this->error)) {
+            throw new ProgrammingError('Inspection object used after error');
+        }
+        Logger::error($entry);
+        $this->log[] = $entry;
+        $this->error = $entry;
+        return $this;
+    }
+
+    /**
+     * If the inspection resulted in an error
+     *
+     * @return bool
+     */
+    public function hasError()
+    {
+        return isset($this->error);
+    }
+
+    /**
+     * The error that caused the inspection to fail
+     *
+     * @return Inspection|string
+     */
+    public function getError()
+    {
+        return $this->error;
+    }
+
+    /**
+     * Convert the inspection to an array
+     *
+     * @return array     An array of strings that describe the state in a human-readable form, each array element
+     *                   represents one log entry about this object.
+     */
+    public function toArray()
+    {
+        return $this->log;
+    }
+
+    /**
+     * Return a text representation of the inspection log entries
+     */
+    public function __toString()
+    {
+        return sprintf(
+            'Inspection: description: "%s" error: "%s"',
+            $this->description,
+            $this->error
+        );
+    }
+}
diff --git a/library/Icinga/Data/Limitable.php b/library/Icinga/Data/Limitable.php
new file mode 100644
index 0000000..8591a79
--- /dev/null
+++ b/library/Icinga/Data/Limitable.php
@@ -0,0 +1,48 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * Interface for retrieving just a portion of a result set
+ */
+interface Limitable
+{
+    /**
+     * Set a limit count and offset
+     *
+     * @param   int $count  Number of rows to return
+     * @param   int $offset Start returning after this many rows
+     *
+     * @return  self
+     */
+    public function limit($count = null, $offset = null);
+
+    /**
+     * Whether a limit is set
+     *
+     * @return bool
+     */
+    public function hasLimit();
+
+    /**
+     * Get the limit if any
+     *
+     * @return int|null
+     */
+    public function getLimit();
+
+    /**
+     * Whether an offset is set
+     *
+     * @return bool
+     */
+    public function hasOffset();
+
+    /**
+     * Get the offset if any
+     *
+     * @return int|null
+     */
+    public function getOffset();
+}
diff --git a/library/Icinga/Data/Paginatable.php b/library/Icinga/Data/Paginatable.php
new file mode 100644
index 0000000..468cca2
--- /dev/null
+++ b/library/Icinga/Data/Paginatable.php
@@ -0,0 +1,10 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Countable;
+
+interface Paginatable extends Limitable, Countable
+{
+}
diff --git a/library/Icinga/Data/PivotTable.php b/library/Icinga/Data/PivotTable.php
new file mode 100644
index 0000000..6c7f806
--- /dev/null
+++ b/library/Icinga/Data/PivotTable.php
@@ -0,0 +1,396 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Data\Filter\Filter;
+use Icinga\Application\Icinga;
+use Icinga\Web\Paginator\Adapter\QueryAdapter;
+use Zend_Paginator;
+
+class PivotTable implements Sortable
+{
+    /**
+     * The query to fetch as pivot table
+     *
+     * @var SimpleQuery
+     */
+    protected $baseQuery;
+
+    /**
+     * X-axis pivot column
+     *
+     * @var string
+     */
+    protected $xAxisColumn;
+
+    /**
+     * Y-axis pivot column
+     *
+     * @var string
+     */
+    protected $yAxisColumn;
+
+    /**
+     * Column for sorting the result set
+     *
+     * @var array
+     */
+    protected $order = array();
+
+    /**
+     * The filter being applied on the query for the x-axis
+     *
+     * @var Filter
+     */
+    protected $xAxisFilter;
+
+    /**
+     * The filter being applied on the query for the y-axis
+     *
+     * @var Filter
+     */
+    protected $yAxisFilter;
+
+    /**
+     * The query to fetch the leading x-axis rows and their headers
+     *
+     * @var SimpleQuery
+     */
+    protected $xAxisQuery;
+
+    /**
+     * The query to fetch the leading y-axis rows and their headers
+     *
+     * @var SimpleQuery
+     */
+    protected $yAxisQuery;
+
+    /**
+     * X-axis header column
+     *
+     * @var string|null
+     */
+    protected $xAxisHeader;
+
+    /**
+     * Y-axis header column
+     *
+     * @var string|null
+     */
+    protected $yAxisHeader;
+
+    /**
+     * Create a new pivot table
+     *
+     * @param   SimpleQuery $query          The query to fetch as pivot table
+     * @param   string      $xAxisColumn    X-axis pivot column
+     * @param   string      $yAxisColumn    Y-axis pivot column
+     */
+    public function __construct(SimpleQuery $query, $xAxisColumn, $yAxisColumn)
+    {
+        $this->baseQuery = $query;
+        $this->xAxisColumn = $xAxisColumn;
+        $this->yAxisColumn = $yAxisColumn;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getOrder()
+    {
+        return $this->order;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function hasOrder()
+    {
+        return ! empty($this->order);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function order($field, $direction = null)
+    {
+        $this->order[$field] = $direction;
+        return $this;
+    }
+
+    /**
+     * Set the filter to apply on the query for the x-axis
+     *
+     * @param   Filter  $filter
+     *
+     * @return  $this
+     */
+    public function setXAxisFilter(Filter $filter = null)
+    {
+        $this->xAxisFilter = $filter;
+        return $this;
+    }
+
+    /**
+     * Set the filter to apply on the query for the y-axis
+     *
+     * @param   Filter  $filter
+     *
+     * @return  $this
+     */
+    public function setYAxisFilter(Filter $filter = null)
+    {
+        $this->yAxisFilter = $filter;
+        return $this;
+    }
+
+    /**
+     * Get the x-axis header
+     *
+     * Defaults to {@link $xAxisColumn} in case no x-axis header has been set using {@link setXAxisHeader()}
+     *
+     * @return string
+     */
+    public function getXAxisHeader()
+    {
+        return $this->xAxisHeader !== null ? $this->xAxisHeader : $this->xAxisColumn;
+    }
+
+    /**
+     * Set the x-axis header
+     *
+     * @param   string $xAxisHeader
+     *
+     * @return  $this
+     */
+    public function setXAxisHeader($xAxisHeader)
+    {
+        $this->xAxisHeader = (string) $xAxisHeader;
+        return $this;
+    }
+
+    /**
+     * Get the y-axis header
+     *
+     * Defaults to {@link $yAxisColumn} in case no x-axis header has been set using {@link setYAxisHeader()}
+     *
+     * @return string
+     */
+    public function getYAxisHeader()
+    {
+        return $this->yAxisHeader !== null ? $this->yAxisHeader : $this->yAxisColumn;
+    }
+
+    /**
+     * Set the y-axis header
+     *
+     * @param   string $yAxisHeader
+     *
+     * @return  $this
+     */
+    public function setYAxisHeader($yAxisHeader)
+    {
+        $this->yAxisHeader = (string) $yAxisHeader;
+        return $this;
+    }
+
+    /**
+     * Return the value for the given request parameter
+     *
+     * @param   string  $axis       The axis for which to return the parameter ('x' or 'y')
+     * @param   string  $param      The parameter name to return
+     * @param   int     $default    The default value to return
+     *
+     * @return  int
+     */
+    protected function getPaginationParameter($axis, $param, $default = null)
+    {
+        $request = Icinga::app()->getRequest();
+
+        $value = $request->getParam($param, '');
+        if (strpos($value, ',') > 0) {
+            $parts = explode(',', $value, 2);
+            return intval($parts[$axis === 'x' ? 0 : 1]);
+        }
+
+        return $default !== null ? $default : 0;
+    }
+
+    /**
+     * Query horizontal (x) axis
+     *
+     * @return SimpleQuery
+     */
+    protected function queryXAxis()
+    {
+        if ($this->xAxisQuery === null) {
+            $this->xAxisQuery = clone $this->baseQuery;
+            $this->xAxisQuery->clearGroupingRules();
+            $xAxisHeader = $this->getXAxisHeader();
+            $columns = array($this->xAxisColumn, $xAxisHeader);
+            $this->xAxisQuery->group(array_unique($columns)); // xAxisColumn and header may be the same column
+            $this->xAxisQuery->columns($columns);
+
+            if ($this->xAxisFilter !== null) {
+                $this->xAxisQuery->addFilter($this->xAxisFilter);
+            }
+
+            $this->xAxisQuery->order(
+                $xAxisHeader,
+                isset($this->order[$xAxisHeader]) ? $this->order[$xAxisHeader] : self::SORT_ASC
+            );
+        }
+
+        return $this->xAxisQuery;
+    }
+
+    /**
+     * Query vertical (y) axis
+     *
+     * @return SimpleQuery
+     */
+    protected function queryYAxis()
+    {
+        if ($this->yAxisQuery === null) {
+            $this->yAxisQuery = clone $this->baseQuery;
+            $this->yAxisQuery->clearGroupingRules();
+            $yAxisHeader = $this->getYAxisHeader();
+            $columns = array($this->yAxisColumn, $yAxisHeader);
+            $this->yAxisQuery->group(array_unique($columns)); // yAxisColumn and header may be the same column
+            $this->yAxisQuery->columns($columns);
+
+            if ($this->yAxisFilter !== null) {
+                $this->yAxisQuery->addFilter($this->yAxisFilter);
+            }
+
+            $this->yAxisQuery->order(
+                $yAxisHeader,
+                isset($this->order[$yAxisHeader]) ? $this->order[$yAxisHeader] : self::SORT_ASC
+            );
+        }
+        return $this->yAxisQuery;
+    }
+
+    /**
+     * Return a pagination adapter for the x-axis query
+     *
+     * $limit and $page are taken from the current request if not given.
+     *
+     * @param   int     $limit  The maximum amount of entries to fetch
+     * @param   int     $page   The page to set as current one
+     *
+     * @return  Zend_Paginator
+     */
+    public function paginateXAxis($limit = null, $page = null)
+    {
+        if ($limit === null || $page === null) {
+            if ($limit === null) {
+                $limit = $this->getPaginationParameter('x', 'limit', 20);
+            }
+
+            if ($page === null) {
+                $page = $this->getPaginationParameter('x', 'page', 1);
+            }
+        }
+
+        $query = $this->queryXAxis();
+        $query->limit($limit, $page > 0 ? ($page - 1) * $limit : 0);
+
+        $paginator = new Zend_Paginator(new QueryAdapter($query));
+        $paginator->setItemCountPerPage($limit);
+        $paginator->setCurrentPageNumber($page);
+        return $paginator;
+    }
+
+    /**
+     * Return a pagination adapter for the y-axis query
+     *
+     * $limit and $page are taken from the current request if not given.
+     *
+     * @param   int     $limit  The maximum amount of entries to fetch
+     * @param   int     $page   The page to set as current one
+     *
+     * @return  Zend_Paginator
+     */
+    public function paginateYAxis($limit = null, $page = null)
+    {
+        if ($limit === null || $page === null) {
+            if ($limit === null) {
+                $limit = $this->getPaginationParameter('y', 'limit', 20);
+            }
+
+            if ($page === null) {
+                $page = $this->getPaginationParameter('y', 'page', 1);
+            }
+        }
+
+        $query = $this->queryYAxis();
+        $query->limit($limit, $page > 0 ? ($page - 1) * $limit : 0);
+
+        $paginator = new Zend_Paginator(new QueryAdapter($query));
+        $paginator->setItemCountPerPage($limit);
+        $paginator->setCurrentPageNumber($page);
+        return $paginator;
+    }
+
+    /**
+     * Return the pivot table as an array of pivot data and pivot header
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        if (($this->xAxisFilter === null && $this->yAxisFilter === null)
+            || ($this->xAxisFilter !== null && $this->yAxisFilter !== null)
+        ) {
+            $xAxis = $this->queryXAxis()->fetchPairs();
+            $yAxis = $this->queryYAxis()->fetchPairs();
+            $xAxisKeys = array_keys($xAxis);
+            $yAxisKeys = array_keys($yAxis);
+        } else {
+            if ($this->xAxisFilter !== null) {
+                $xAxis = $this->queryXAxis()->fetchPairs();
+                $xAxisKeys = array_keys($xAxis);
+                $yAxis = $this->queryYAxis()->where($this->xAxisColumn, $xAxisKeys)->fetchPairs();
+                $yAxisKeys = array_keys($yAxis);
+            } else { // $this->yAxisFilter !== null
+                $yAxis = $this->queryYAxis()->fetchPairs();
+                $yAxisKeys = array_keys($yAxis);
+                $xAxis = $this->queryXAxis()->where($this->yAxisColumn, $yAxisKeys)->fetchPairs();
+                $xAxisKeys = array_keys($xAxis);
+            }
+        }
+        $pivotData = array();
+        $pivotHeader = array(
+            'cols'  => $xAxis,
+            'rows'  => $yAxis
+        );
+        if (! empty($xAxis) && ! empty($yAxis)) {
+            $this->baseQuery
+                ->where($this->xAxisColumn, array_map(
+                    function ($key) {
+                        return (string) $key;
+                    },
+                    $xAxisKeys
+                ))
+                ->where($this->yAxisColumn, array_map(
+                    function ($key) {
+                        return (string) $key;
+                    },
+                    $yAxisKeys
+                ));
+
+            foreach ($yAxisKeys as $yAxisKey) {
+                foreach ($xAxisKeys as $xAxisKey) {
+                    $pivotData[$yAxisKey][$xAxisKey] = null;
+                }
+            }
+
+            foreach ($this->baseQuery as $row) {
+                $pivotData[$row->{$this->yAxisColumn}][$row->{$this->xAxisColumn}] = $row;
+            }
+        }
+        return array($pivotData, $pivotHeader);
+    }
+}
diff --git a/library/Icinga/Data/QueryInterface.php b/library/Icinga/Data/QueryInterface.php
new file mode 100644
index 0000000..e723857
--- /dev/null
+++ b/library/Icinga/Data/QueryInterface.php
@@ -0,0 +1,8 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+interface QueryInterface extends Fetchable, Filterable, Paginatable, Sortable
+{
+}
diff --git a/library/Icinga/Data/Queryable.php b/library/Icinga/Data/Queryable.php
new file mode 100644
index 0000000..75cdc98
--- /dev/null
+++ b/library/Icinga/Data/Queryable.php
@@ -0,0 +1,20 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * Interface for specifying data sources
+ */
+interface Queryable
+{
+    /**
+     * Set the target and fields to query
+     *
+     * @param   string  $target
+     * @param   array   $fields
+     *
+     * @return  Fetchable
+     */
+    public function from($target, array $fields = null);
+}
diff --git a/library/Icinga/Data/Reducible.php b/library/Icinga/Data/Reducible.php
new file mode 100644
index 0000000..6ece17e
--- /dev/null
+++ b/library/Icinga/Data/Reducible.php
@@ -0,0 +1,23 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Data\Filter\Filter;
+use Icinga\Exception\StatementException;
+
+/**
+ * Interface for data deletion
+ */
+interface Reducible
+{
+    /**
+     * Delete entries in the given target, optionally limiting the affected entries by using a filter
+     *
+     * @param   string  $target
+     * @param   Filter  $filter
+     *
+     * @throws  StatementException
+     */
+    public function delete($target, Filter $filter = null);
+}
diff --git a/library/Icinga/Data/ResourceFactory.php b/library/Icinga/Data/ResourceFactory.php
new file mode 100644
index 0000000..5b477c7
--- /dev/null
+++ b/library/Icinga/Data/ResourceFactory.php
@@ -0,0 +1,138 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Application\Config;
+use Icinga\Util\ConfigAwareFactory;
+use Icinga\Exception\ConfigurationError;
+use Icinga\Data\Db\DbConnection;
+use Icinga\Protocol\Ldap\LdapConnection;
+use Icinga\Protocol\File\FileReader;
+
+/**
+ * Create resources from names or resource configuration
+ */
+class ResourceFactory implements ConfigAwareFactory
+{
+    /**
+     * Resource configuration
+     *
+     * @var Config
+     */
+    private static $resources;
+
+    /**
+     * Set resource configurations
+     *
+     * @param Config $config
+     */
+    public static function setConfig($config)
+    {
+        self::$resources = $config;
+    }
+
+    /**
+     * Get the configuration for a specific resource
+     *
+     * @param   $resourceName   String      The resource's name
+     *
+     * @return                  ConfigObject    The configuration of the resource
+     *
+     * @throws                  ConfigurationError
+     */
+    public static function getResourceConfig($resourceName)
+    {
+        self::assertResourcesExist();
+        $resourceConfig = self::$resources->getSection($resourceName);
+        if ($resourceConfig->isEmpty()) {
+            throw new ConfigurationError(
+                'Cannot load resource config "%s". Resource does not exist',
+                $resourceName
+            );
+        }
+        return $resourceConfig;
+    }
+
+    /**
+     * Get the configuration of all existing resources, or all resources of the given type
+     *
+     * @param   string  $type   Filter for resource type
+     *
+     * @return  Config          The resources configuration
+     */
+    public static function getResourceConfigs($type = null)
+    {
+        self::assertResourcesExist();
+        if ($type === null) {
+            return self::$resources;
+        }
+        $resources = array();
+        foreach (self::$resources as $name => $resource) {
+            if ($resource->get('type') === $type) {
+                $resources[$name] = $resource;
+            }
+        }
+        return Config::fromArray($resources);
+    }
+
+    /**
+     * Check if the existing resources are set. If not, load them from resources.ini
+     *
+     * @throws  ConfigurationError
+     */
+    private static function assertResourcesExist()
+    {
+        if (self::$resources === null) {
+            self::$resources = Config::app('resources');
+        }
+    }
+
+    /**
+     * Create and return a resource based on the given configuration
+     *
+     * @param   ConfigObject    $config     The configuration of the resource to create
+     *
+     * @return  Selectable                  The resource
+     * @throws  ConfigurationError          In case of an unsupported type or invalid configuration
+     */
+    public static function createResource(ConfigObject $config)
+    {
+        switch (strtolower($config->type)) {
+            case 'db':
+                $resource = new DbConnection($config);
+                break;
+            case 'ldap':
+                if (empty($config->root_dn)) {
+                    throw new ConfigurationError('LDAP root DN missing');
+                }
+
+                $resource = new LdapConnection($config);
+                break;
+            case 'file':
+                $resource = new FileReader($config);
+                break;
+            case 'ini':
+                $resource = Config::fromIni($config->ini);
+                break;
+            default:
+                throw new ConfigurationError(
+                    'Unsupported resource type "%s"',
+                    $config->type
+                );
+        }
+
+        return $resource;
+    }
+
+    /**
+     * Create a resource from name
+     *
+     * @param   string  $resourceName
+     * @return  DbConnection|LdapConnection
+     */
+    public static function create($resourceName)
+    {
+        return self::createResource(self::getResourceConfig($resourceName));
+    }
+}
diff --git a/library/Icinga/Data/Selectable.php b/library/Icinga/Data/Selectable.php
new file mode 100644
index 0000000..ace4e79
--- /dev/null
+++ b/library/Icinga/Data/Selectable.php
@@ -0,0 +1,17 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * Interface for classes providing a data source to fetch data from
+ */
+interface Selectable
+{
+    /**
+     * Provide a data source to fetch data from
+     *
+     * @return Queryable
+     */
+    public function select();
+}
diff --git a/library/Icinga/Data/SimpleQuery.php b/library/Icinga/Data/SimpleQuery.php
new file mode 100644
index 0000000..1ef0c27
--- /dev/null
+++ b/library/Icinga/Data/SimpleQuery.php
@@ -0,0 +1,650 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Iterator;
+use IteratorAggregate;
+use Icinga\Application\Benchmark;
+use Icinga\Data\Filter\Filter;
+use Icinga\Exception\IcingaException;
+use Icinga\Exception\ProgrammingError;
+
+class SimpleQuery implements QueryInterface, Queryable, Iterator
+{
+    /**
+     * Query data source
+     *
+     * @var mixed
+     */
+    protected $ds;
+
+    /**
+     * This query's iterator
+     *
+     * @var Iterator
+     */
+    protected $iterator;
+
+    /**
+     * The current position of this query's iterator
+     *
+     * @var int
+     */
+    protected $iteratorPosition;
+
+    /**
+     * The amount of rows previously calculated
+     *
+     * @var int
+     */
+    protected $cachedCount;
+
+    /**
+     * The target you are going to query
+     *
+     * @var mixed
+     */
+    protected $target;
+
+    /**
+     * The columns you asked for
+     *
+     * All columns if null, no column if empty??? Alias handling goes here!
+     *
+     * @var array
+     */
+    protected $desiredColumns = array();
+
+    /**
+     * The columns you are interested in
+     *
+     * All columns if null, no column if empty??? Alias handling goes here!
+     *
+     * @var array
+     */
+    protected $columns = array();
+
+    /**
+     * The columns and their aliases flipped in order to handle aliased sort columns
+     *
+     * Supposed to be used and populated by $this->compare *only*.
+     *
+     * @var array
+     */
+    protected $flippedColumns;
+
+    /**
+     * The columns you're using to sort the query result
+     *
+     * @var array
+     */
+    protected $order = array();
+
+    /**
+     * Number of rows to return
+     *
+     * @var int
+     */
+    protected $limitCount;
+
+    /**
+     * Result starts with this row
+     *
+     * @var int
+     */
+    protected $limitOffset;
+
+    /**
+     * Whether to peek ahead for more results
+     *
+     * @var bool
+     */
+    protected $peekAhead;
+
+    /**
+     * Whether the query did not yield all available results
+     *
+     * @var bool
+     */
+    protected $hasMore;
+
+    protected $filter;
+
+    /**
+     * Constructor
+     *
+     * @param mixed $ds
+     */
+    public function __construct($ds, $columns = null)
+    {
+        $this->ds = $ds;
+        $this->filter = Filter::matchAll();
+        if ($columns !== null) {
+            $this->desiredColumns = $columns;
+        }
+        $this->init();
+        if ($this->desiredColumns !== null) {
+            $this->columns($this->desiredColumns);
+        }
+    }
+
+    /**
+     * Initialize query
+     *
+     * Overwrite this instead of __construct (it's called at the end of the construct) to
+     * implement custom initialization logic on construction time
+     */
+    protected function init()
+    {
+    }
+
+    /**
+     * Get the data source
+     *
+     * @return mixed
+     */
+    public function getDatasource()
+    {
+        return $this->ds;
+    }
+
+    /**
+     * Return the current position of this query's iterator
+     *
+     * @return  int
+     */
+    public function getIteratorPosition()
+    {
+        return $this->iteratorPosition;
+    }
+
+    /**
+     * Start or rewind the iteration
+     */
+    public function rewind(): void
+    {
+        if ($this->iterator === null) {
+            $iterator = $this->ds->query($this);
+            if ($iterator instanceof IteratorAggregate) {
+                $this->iterator = $iterator->getIterator();
+            } else {
+                $this->iterator = $iterator;
+            }
+        }
+
+        $this->iterator->rewind();
+        $this->iteratorPosition = null;
+        Benchmark::measure('Query result iteration started');
+    }
+
+    /**
+     * Fetch and return the current row of this query's result
+     *
+     * @return  mixed
+     */
+    #[\ReturnTypeWillChange]
+    public function current()
+    {
+        return $this->iterator->current();
+    }
+
+    /**
+     * Return whether the current row of this query's result is valid
+     *
+     * @return  bool
+     */
+    public function valid(): bool
+    {
+        $valid = $this->iterator->valid();
+        if ($valid && $this->peekAhead && $this->hasLimit() && $this->iteratorPosition + 1 === $this->getLimit()) {
+            $this->hasMore = true;
+            $valid = false; // We arrived at the last result, which is the requested extra row, so stop the iteration
+        } elseif (! $valid) {
+            $this->hasMore = false;
+        }
+
+        if (! $valid) {
+            Benchmark::measure('Query result iteration finished');
+            return false;
+        } elseif ($this->iteratorPosition === null) {
+            $this->iteratorPosition = 0;
+        }
+
+        return true;
+    }
+
+    /**
+     * Return the key for the current row of this query's result
+     *
+     * @return  mixed
+     */
+    #[\ReturnTypeWillChange]
+    public function key()
+    {
+        return $this->iterator->key();
+    }
+
+    /**
+     * Advance to the next row of this query's result
+     */
+    public function next(): void
+    {
+        $this->iterator->next();
+        $this->iteratorPosition += 1;
+    }
+
+    /**
+     * Choose a table and the columns you are interested in
+     *
+     * Query will return all available columns if none are given here.
+     *
+     * @param   mixed   $target
+     * @param   array   $fields
+     *
+     * @return  $this
+     */
+    public function from($target, array $fields = null)
+    {
+        $this->target = $target;
+        if ($fields !== null) {
+            $this->columns($fields);
+        }
+        return $this;
+    }
+
+    /**
+     * Add a where condition to the query by and
+     *
+     * The syntax of the condition and valid values are defined by the concrete backend-specific query implementation.
+     *
+     * @param   string  $condition
+     * @param   mixed   $value
+     *
+     * @return  $this
+     */
+    public function where($condition, $value = null)
+    {
+        // TODO: more intelligence please
+        $this->filter->addFilter(Filter::expression($condition, '=', $value));
+        return $this;
+    }
+
+    public function getFilter()
+    {
+        return $this->filter;
+    }
+
+    public function applyFilter(Filter $filter)
+    {
+        return $this->addFilter($filter);
+    }
+
+    public function addFilter(Filter $filter)
+    {
+        $this->filter->addFilter($filter);
+        return $this;
+    }
+
+    public function setFilter(Filter $filter)
+    {
+        $this->filter = $filter;
+        return $this;
+    }
+
+    public function setOrderColumns(array $orderColumns)
+    {
+        throw new IcingaException('This function does nothing and will be removed');
+    }
+
+    /**
+     * Split order field into its field and sort direction
+     *
+     * @param   string  $field
+     *
+     * @return  array
+     */
+    public function splitOrder($field)
+    {
+        $fieldAndDirection = explode(' ', $field, 2);
+        if (count($fieldAndDirection) === 1) {
+            $direction = null;
+        } else {
+            $field = $fieldAndDirection[0];
+            $direction = (strtoupper(trim($fieldAndDirection[1])) === 'DESC') ?
+                Sortable::SORT_DESC : Sortable::SORT_ASC;
+        }
+        return array($field, $direction);
+    }
+
+    /**
+     * Sort result set by the given field (and direction)
+     *
+     * Preferred usage:
+     * <code>
+     * $query->order('field, 'ASC')
+     * </code>
+     *
+     * @param  string   $field
+     * @param  string   $direction
+     *
+     * @return $this
+     */
+    public function order($field, $direction = null)
+    {
+        if ($direction === null) {
+            list($field, $direction) = $this->splitOrder($field);
+            if ($direction === null) {
+                $direction = Sortable::SORT_ASC;
+            }
+        } else {
+            switch (($direction = strtoupper($direction))) {
+                case Sortable::SORT_ASC:
+                case Sortable::SORT_DESC:
+                    break;
+                default:
+                    $direction = Sortable::SORT_ASC;
+                    break;
+            }
+        }
+        $this->order[] = array($field, $direction);
+        return $this;
+    }
+
+    /**
+     * Compare $a with $b based on this query's sort rules and column aliases
+     *
+     * @param   object  $a
+     * @param   object  $b
+     * @param   int     $orderIndex
+     *
+     * @return  int
+     */
+    public function compare($a, $b, $orderIndex = 0)
+    {
+        if (! array_key_exists($orderIndex, $this->order)) {
+            return 0; // Last column to sort reached, rows are considered being equal
+        }
+
+        if ($this->flippedColumns === null) {
+            $this->flippedColumns = array_flip($this->columns);
+        }
+
+        $column = $this->order[$orderIndex][0];
+        if (array_key_exists($column, $this->flippedColumns) && is_string($this->flippedColumns[$column])) {
+            $column = $this->flippedColumns[$column];
+        }
+
+        $result = strcmp(strtolower($a->$column ?? ''), strtolower($b->$column ?? ''));
+        if ($result === 0) {
+            return $this->compare($a, $b, ++$orderIndex);
+        }
+
+        $direction = $this->order[$orderIndex][1];
+        if ($direction === self::SORT_ASC) {
+            return $result;
+        } else {
+            return $result * -1;
+        }
+    }
+
+    /**
+     * Clear the order if any
+     *
+     * @return $this
+     */
+    public function clearOrder()
+    {
+        $this->order = array();
+        return $this;
+    }
+
+    /**
+     * Whether an order is set
+     *
+     * @return bool
+     */
+    public function hasOrder()
+    {
+        return ! empty($this->order);
+    }
+
+    /**
+     * Get the order
+     *
+     * @return array
+     */
+    public function getOrder()
+    {
+        return $this->order;
+    }
+
+    /**
+     * Set whether this query should peek ahead for more results
+     *
+     * Enabling this causes the current query limit to be increased by one. The potential extra row being yielded will
+     * be removed from the result set. Note that this only applies when fetching multiple results of limited queries.
+     *
+     * @return  $this
+     */
+    public function peekAhead($state = true)
+    {
+        $this->peekAhead = (bool) $state;
+        return $this;
+    }
+
+    /**
+     * Return whether this query did not yield all available results
+     *
+     * @return  bool
+     *
+     * @throws  ProgrammingError    In case the query did not run yet
+     */
+    public function hasMore()
+    {
+        if ($this->hasMore === null) {
+            throw new ProgrammingError('Query did not run. Cannot determine whether there are more results.');
+        }
+
+        return $this->hasMore;
+    }
+
+    /**
+     * Return whether this query will or has yielded any result
+     *
+     * @return  bool
+     */
+    public function hasResult()
+    {
+        return $this->cachedCount > 0 || $this->iteratorPosition !== null || $this->fetchRow() !== false;
+    }
+
+    /**
+     * Set a limit count and offset to the query
+     *
+     * @param   int $count  Number of rows to return
+     * @param   int $offset Start returning after this many rows
+     *
+     * @return  $this
+     */
+    public function limit($count = null, $offset = null)
+    {
+        $this->limitCount = $count !== null ? (int) $count : null;
+        $this->limitOffset = (int) $offset;
+        return $this;
+    }
+
+    /**
+     * Whether a limit is set
+     *
+     * @return bool
+     */
+    public function hasLimit()
+    {
+        return $this->limitCount !== null && $this->limitCount > 0;
+    }
+
+    /**
+     * Get the limit if any
+     *
+     * @return int|null
+     */
+    public function getLimit()
+    {
+        return $this->peekAhead && $this->hasLimit() ? $this->limitCount + 1 : $this->limitCount;
+    }
+
+    /**
+     * Whether an offset is set
+     *
+     * @return bool
+     */
+    public function hasOffset()
+    {
+        return $this->limitOffset > 0;
+    }
+
+    /**
+     * Get the offset if any
+     *
+     * @return int|null
+     */
+    public function getOffset()
+    {
+        return $this->limitOffset;
+    }
+
+    /**
+     * Retrieve an array containing all rows of the result set
+     *
+     * @return array
+     */
+    public function fetchAll()
+    {
+        Benchmark::measure('Fetching all results started');
+        $results = $this->ds->fetchAll($this);
+        Benchmark::measure('Fetching all results finished');
+
+        if ($this->peekAhead && $this->hasLimit() && count($results) === $this->getLimit()) {
+            $this->hasMore = true;
+            array_pop($results);
+        } else {
+            $this->hasMore = false;
+        }
+
+        return $results;
+    }
+
+    /**
+     * Fetch the first row of the result set
+     *
+     * @return mixed
+     */
+    public function fetchRow()
+    {
+        Benchmark::measure('Fetching one row started');
+        $row = $this->ds->fetchRow($this);
+        Benchmark::measure('Fetching one row finished');
+        return $row;
+    }
+
+    /**
+     * Fetch the first column of all rows of the result set as an array
+     *
+     * @return  array
+     */
+    public function fetchColumn()
+    {
+        Benchmark::measure('Fetching one column started');
+        $values = $this->ds->fetchColumn($this);
+        Benchmark::measure('Fetching one column finished');
+
+        if ($this->peekAhead && $this->hasLimit() && count($values) === $this->getLimit()) {
+            $this->hasMore = true;
+            array_pop($values);
+        } else {
+            $this->hasMore = false;
+        }
+
+        return $values;
+    }
+
+    /**
+     * Fetch the first column of the first row of the result set
+     *
+     * @return string
+     */
+    public function fetchOne()
+    {
+        Benchmark::measure('Fetching one value started');
+        $value = $this->ds->fetchOne($this);
+        Benchmark::measure('Fetching one value finished');
+        return $value;
+    }
+
+    /**
+     * Fetch all rows of the result set as an array of key-value pairs
+     *
+     * The first column is the key, the second column is the value.
+     *
+     * @return array
+     */
+    public function fetchPairs()
+    {
+        Benchmark::measure('Fetching pairs started');
+        $pairs = $this->ds->fetchPairs($this);
+        Benchmark::measure('Fetching pairs finished');
+
+        if ($this->peekAhead && $this->hasLimit() && count($pairs) === $this->getLimit()) {
+            $this->hasMore = true;
+            array_pop($pairs);
+        } else {
+            $this->hasMore = false;
+        }
+
+        return $pairs;
+    }
+
+    /**
+     * Count all rows of the result set, ignoring limit and offset
+     *
+     * @return  int
+     */
+    public function count(): int
+    {
+        $query = clone $this;
+        $query->limit(0, 0);
+        Benchmark::measure('Counting all results started');
+        $count = $this->ds->count($query);
+        $this->cachedCount = $count;
+        Benchmark::measure('Counting all results finished');
+        return $count;
+    }
+
+    /**
+     * Set columns
+     *
+     * @param   array $columns
+     *
+     * @return  $this
+     */
+    public function columns(array $columns)
+    {
+        $this->columns = $columns;
+        $this->flippedColumns = null; // Reset, due to updated columns
+        return $this;
+    }
+
+    public function getColumns()
+    {
+        return $this->columns;
+    }
+
+    /**
+     * Deep clone self::$filter
+     */
+    public function __clone()
+    {
+        $this->filter = clone $this->filter;
+    }
+}
diff --git a/library/Icinga/Data/SortRules.php b/library/Icinga/Data/SortRules.php
new file mode 100644
index 0000000..c93bdda
--- /dev/null
+++ b/library/Icinga/Data/SortRules.php
@@ -0,0 +1,14 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+interface SortRules
+{
+    /**
+     * Return some sort rules
+     *
+     * @return  array
+     */
+    public function getSortRules();
+}
diff --git a/library/Icinga/Data/Sortable.php b/library/Icinga/Data/Sortable.php
new file mode 100644
index 0000000..11d38c3
--- /dev/null
+++ b/library/Icinga/Data/Sortable.php
@@ -0,0 +1,49 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+/**
+ * Interface for sorting a result set
+ */
+interface Sortable
+{
+    /**
+     * Sort ascending
+     */
+    const SORT_ASC = 'ASC';
+
+    /**
+     * Sort descending
+     */
+    const SORT_DESC  = 'DESC';
+
+    /**
+     * Sort result set by the given field (and direction)
+     *
+     * Preferred usage:
+     * <code>
+     * $query->order('field, 'ASC')
+     * </code>
+     *
+     * @param  string   $field
+     * @param  string   $direction
+     *
+     * @return self
+     */
+    public function order($field, $direction = null);
+
+    /**
+     * Whether an order is set
+     *
+     * @return bool
+     */
+    public function hasOrder();
+
+    /**
+     * Get the order if any
+     *
+     * @return array|null
+     */
+    public function getOrder();
+}
diff --git a/library/Icinga/Data/Tree/SimpleTree.php b/library/Icinga/Data/Tree/SimpleTree.php
new file mode 100644
index 0000000..e89f589
--- /dev/null
+++ b/library/Icinga/Data/Tree/SimpleTree.php
@@ -0,0 +1,90 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Tree;
+
+use IteratorAggregate;
+use LogicException;
+use Traversable;
+
+/**
+ * A simple tree
+ */
+class SimpleTree implements IteratorAggregate
+{
+    /**
+     * Root node
+     *
+     * @var TreeNode
+     */
+    protected $sentinel;
+
+    /**
+     * Nodes
+     *
+     * @var array
+     */
+    protected $nodes = array();
+
+    /**
+     * Create a new simple tree
+     */
+    public function __construct()
+    {
+        $this->sentinel = new TreeNode();
+    }
+
+    /**
+     * Add a child node
+     *
+     * @param   TreeNode $child
+     * @param   TreeNode $parent
+     *
+     * @return $this
+     */
+    public function addChild(TreeNode $child, TreeNode $parent = null)
+    {
+        if ($parent === null) {
+            $parent = $this->sentinel;
+        } elseif (! isset($this->nodes[$parent->getId()])) {
+            throw new LogicException(sprintf(
+                'Can\'t append child node %s to parent node %s: Parent node does not exist',
+                $child->getId(),
+                $parent->getId()
+            ));
+        }
+        if (isset($this->nodes[$child->getId()])) {
+            throw new LogicException(sprintf(
+                'Can\'t append child node %s to parent node %s: Child node does already exist',
+                $child->getId(),
+                $parent->getId()
+            ));
+        }
+        $this->nodes[$child->getId()] = $child;
+        $parent->appendChild($child);
+        return $this;
+    }
+
+    /**
+     * Get a node by its ID
+     *
+     * @param   mixed   $id
+     *
+     * @return  TreeNode|null
+     */
+    public function getNode($id)
+    {
+        if (! isset($this->nodes[$id])) {
+            return null;
+        }
+        return $this->nodes[$id];
+    }
+
+    /**
+     * @return TreeNodeIterator
+     */
+    public function getIterator(): Traversable
+    {
+        return new TreeNodeIterator($this->sentinel);
+    }
+}
diff --git a/library/Icinga/Data/Tree/TreeNode.php b/library/Icinga/Data/Tree/TreeNode.php
new file mode 100644
index 0000000..66bce79
--- /dev/null
+++ b/library/Icinga/Data/Tree/TreeNode.php
@@ -0,0 +1,109 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Tree;
+
+use Icinga\Data\Identifiable;
+
+class TreeNode implements Identifiable
+{
+    /**
+     * The node's ID
+     *
+     * @var mixed
+     */
+    protected $id;
+
+    /**
+     * The node's value
+     *
+     * @var mixed
+     */
+    protected $value;
+
+    /**
+     * The node's children
+     *
+     * @var array
+     */
+    protected $children = array();
+
+    /**
+     * Set the node's ID
+     *
+     * @param   mixed   $id ID of the node
+     *
+     * @return  $this
+     */
+    public function setId($id)
+    {
+        $this->id = $id;
+        return $this;
+    }
+
+    /**
+     * (non-PHPDoc)
+     * @see Identifiable::getId() For the method documentation.
+     */
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set the node's value
+     *
+     * @param   mixed   $value
+     *
+     * @return  $this
+     */
+    public function setValue($value)
+    {
+        $this->value = $value;
+        return $this;
+    }
+
+    /**
+     * Get the node's value
+     *
+     * @return mixed
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+
+    /**
+     * Append a child node as the last child of this node
+     *
+     * @param   TreeNode    $child  The child to append
+     *
+     * @return  $this
+     */
+    public function appendChild(TreeNode $child)
+    {
+        $this->children[] = $child;
+        return $this;
+    }
+
+
+    /**
+     * Get whether the node has children
+     *
+     * @return bool
+     */
+    public function hasChildren()
+    {
+        return ! empty($this->children);
+    }
+
+    /**
+     * Get the node's children
+     *
+     * @return array
+     */
+    public function getChildren()
+    {
+        return $this->children;
+    }
+}
diff --git a/library/Icinga/Data/Tree/TreeNodeIterator.php b/library/Icinga/Data/Tree/TreeNodeIterator.php
new file mode 100644
index 0000000..1c71787
--- /dev/null
+++ b/library/Icinga/Data/Tree/TreeNodeIterator.php
@@ -0,0 +1,75 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data\Tree;
+
+use ArrayIterator;
+use RecursiveIterator;
+
+/**
+ * Iterator over a tree node's children
+ */
+class TreeNodeIterator implements RecursiveIterator
+{
+    /**
+     * The node's children
+     *
+     * @var ArrayIterator
+     */
+    protected $children;
+
+    /**
+     * Create a new iterator over a tree node's children
+     *
+     * @param TreeNode $node
+     */
+    public function __construct(TreeNode $node)
+    {
+        $this->children = new ArrayIterator($node->getChildren());
+    }
+
+    public function current(): TreeNode
+    {
+        return $this->children->current();
+    }
+
+    public function key(): int
+    {
+        return $this->children->key();
+    }
+
+    public function next(): void
+    {
+        $this->children->next();
+    }
+
+    public function rewind(): void
+    {
+        $this->children->rewind();
+    }
+
+    public function valid(): bool
+    {
+        return $this->children->valid();
+    }
+
+    public function hasChildren(): bool
+    {
+        return $this->current()->hasChildren();
+    }
+
+    public function getChildren(): TreeNodeIterator
+    {
+        return new static($this->current());
+    }
+
+    /**
+     * Get whether the iterator is empty
+     *
+     * @return bool
+     */
+    public function isEmpty()
+    {
+        return ! $this->children->count();
+    }
+}
diff --git a/library/Icinga/Data/Updatable.php b/library/Icinga/Data/Updatable.php
new file mode 100644
index 0000000..ff70b99
--- /dev/null
+++ b/library/Icinga/Data/Updatable.php
@@ -0,0 +1,24 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Data;
+
+use Icinga\Data\Filter\Filter;
+use Icinga\Exception\StatementException;
+
+/**
+ * Interface for data updating
+ */
+interface Updatable
+{
+    /**
+     * Update the target with the given data and optionally limit the affected entries by using a filter
+     *
+     * @param   string  $target
+     * @param   array   $data
+     * @param   Filter  $filter
+     *
+     * @throws  StatementException
+     */
+    public function update($target, array $data, Filter $filter = null);
+}