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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 17:41:08 +0000
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Adding upstream version 3.1.7.upstream/3.1.7upstream
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+.. currentmodule:: psycopg
+
+Other top-level objects
+=======================
+
+Connection information
+----------------------
+
+.. autoclass:: ConnectionInfo()
+
+ The object is usually returned by `Connection.info`.
+
+ .. autoattribute:: dsn
+
+ .. note:: The `get_parameters()` method returns the same information
+ as a dict.
+
+ .. autoattribute:: status
+
+ The status can be one of a number of values. However, only two of
+ these are seen outside of an asynchronous connection procedure:
+ `~pq.ConnStatus.OK` and `~pq.ConnStatus.BAD`. A good connection to the
+ database has the status `!OK`. Ordinarily, an `!OK` status will remain
+ so until `Connection.close()`, but a communications failure might
+ result in the status changing to `!BAD` prematurely.
+
+ .. autoattribute:: transaction_status
+
+ The status can be `~pq.TransactionStatus.IDLE` (currently idle),
+ `~pq.TransactionStatus.ACTIVE` (a command is in progress),
+ `~pq.TransactionStatus.INTRANS` (idle, in a valid transaction block),
+ or `~pq.TransactionStatus.INERROR` (idle, in a failed transaction
+ block). `~pq.TransactionStatus.UNKNOWN` is reported if the connection
+ is bad. `!ACTIVE` is reported only when a query has been sent to the
+ server and not yet completed.
+
+ .. autoattribute:: pipeline_status
+
+ .. autoattribute:: backend_pid
+ .. autoattribute:: vendor
+
+ Normally it is `PostgreSQL`; it may be different if connected to
+ a different database.
+
+ .. versionadded:: 3.1
+
+ .. autoattribute:: server_version
+
+ The number is formed by converting the major, minor, and revision
+ numbers into two-decimal-digit numbers and appending them together.
+ Starting from PostgreSQL 10 the minor version was dropped, so the
+ second group of digits is always 00. For example, version 9.3.5 is
+ returned as 90305, version 10.2 as 100002.
+
+ .. autoattribute:: error_message
+
+ .. automethod:: get_parameters
+
+ .. note:: The `dsn` attribute returns the same information in the form
+ as a string.
+
+ .. autoattribute:: timezone
+
+ .. code:: pycon
+
+ >>> conn.info.timezone
+ zoneinfo.ZoneInfo(key='Europe/Rome')
+
+ .. autoattribute:: host
+
+ This can be a host name, an IP address, or a directory path if the
+ connection is via Unix socket. (The path case can be distinguished
+ because it will always be an absolute path, beginning with ``/``.)
+
+ .. autoattribute:: hostaddr
+
+ Only available if the libpq used is at least from PostgreSQL 12.
+ Raise `~psycopg.NotSupportedError` otherwise.
+
+ .. autoattribute:: port
+ .. autoattribute:: dbname
+ .. autoattribute:: user
+ .. autoattribute:: password
+ .. autoattribute:: options
+ .. automethod:: parameter_status
+
+ Example of parameters are ``server_version``,
+ ``standard_conforming_strings``... See :pq:`PQparameterStatus()` for
+ all the available parameters.
+
+ .. autoattribute:: encoding
+
+ The value returned is always normalized to the Python codec
+ `~codecs.CodecInfo.name`::
+
+ conn.execute("SET client_encoding TO LATIN9")
+ conn.info.encoding
+ 'iso8859-15'
+
+ A few PostgreSQL encodings are not available in Python and cannot be
+ selected (currently ``EUC_TW``, ``MULE_INTERNAL``). The PostgreSQL
+ ``SQL_ASCII`` encoding has the special meaning of "no encoding": see
+ :ref:`adapt-string` for details.
+
+ .. seealso::
+
+ The `PostgreSQL supported encodings`__.
+
+ .. __: https://www.postgresql.org/docs/current/multibyte.html
+
+
+The description `Column` object
+-------------------------------
+
+.. autoclass:: Column()
+
+ An object describing a column of data from a database result, `as described
+ by the DBAPI`__, so it can also be unpacked as a 7-items tuple.
+
+ The object is returned by `Cursor.description`.
+
+ .. __: https://www.python.org/dev/peps/pep-0249/#description
+
+ .. autoattribute:: name
+ .. autoattribute:: type_code
+ .. autoattribute:: display_size
+ .. autoattribute:: internal_size
+ .. autoattribute:: precision
+ .. autoattribute:: scale
+
+
+Notifications
+-------------
+
+.. autoclass:: Notify()
+
+ The object is usually returned by `Connection.notifies()`.
+
+ .. attribute:: channel
+ :type: str
+
+ The name of the channel on which the notification was received.
+
+ .. attribute:: payload
+ :type: str
+
+ The message attached to the notification.
+
+ .. attribute:: pid
+ :type: int
+
+ The PID of the backend process which sent the notification.
+
+
+Pipeline-related objects
+------------------------
+
+See :ref:`pipeline-mode` for details.
+
+.. autoclass:: Pipeline
+
+ This objects is returned by `Connection.pipeline()`.
+
+ .. automethod:: sync
+ .. automethod:: is_supported
+
+
+.. autoclass:: AsyncPipeline
+
+ This objects is returned by `AsyncConnection.pipeline()`.
+
+ .. automethod:: sync
+
+
+Transaction-related objects
+---------------------------
+
+See :ref:`transactions` for details about these objects.
+
+.. autoclass:: IsolationLevel
+ :members:
+
+ The value is usually used with the `Connection.isolation_level` property.
+
+ Check the PostgreSQL documentation for a description of the effects of the
+ different `levels of transaction isolation`__.
+
+ .. __: https://www.postgresql.org/docs/current/transaction-iso.html
+
+
+.. autoclass:: Transaction()
+
+ .. autoattribute:: savepoint_name
+ .. autoattribute:: connection
+
+
+.. autoclass:: AsyncTransaction()
+
+ .. autoattribute:: connection
+
+
+.. autoexception:: Rollback
+
+ It can be used as:
+
+ - ``raise Rollback``: roll back the operation that happened in the current
+ transaction block and continue the program after the block.
+
+ - ``raise Rollback()``: same effect as above
+
+ - :samp:`raise Rollback({tx})`: roll back any operation that happened in
+ the `Transaction` `!tx` (returned by a statement such as :samp:`with
+ conn.transaction() as {tx}:` and all the blocks nested within. The
+ program will continue after the `!tx` block.
+
+
+Two-Phase Commit related objects
+--------------------------------
+
+.. autoclass:: Xid()
+
+ See :ref:`two-phase-commit` for details.
+
+ .. autoattribute:: format_id
+
+ Format Identifier of the two-phase transaction.
+
+ .. autoattribute:: gtrid
+
+ Global Transaction Identifier of the two-phase transaction.
+
+ If the Xid doesn't follow the XA standard, it will be the PostgreSQL
+ ID of the transaction (in which case `format_id` and `bqual` will be
+ `!None`).
+
+ .. autoattribute:: bqual
+
+ Branch Qualifier of the two-phase transaction.
+
+ .. autoattribute:: prepared
+
+ Timestamp at which the transaction was prepared for commit.
+
+ Only available on transactions recovered by `~Connection.tpc_recover()`.
+
+ .. autoattribute:: owner
+
+ Named of the user that executed the transaction.
+
+ Only available on recovered transactions.
+
+ .. autoattribute:: database
+
+ Named of the database in which the transaction was executed.
+
+ Only available on recovered transactions.