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-- Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; version 2 of the License.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program; if not, write to the Free Software
-- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
DROP PROCEDURE IF EXISTS table_exists;
DELIMITER $$
CREATE DEFINER='mariadb.sys'@'localhost' PROCEDURE table_exists (
IN in_db VARCHAR(64), IN in_table VARCHAR(64),
OUT out_exists ENUM('', 'BASE TABLE', 'VIEW', 'TEMPORARY', 'SEQUENCE', 'SYSTEM VIEW', 'TEMPORARY SEQUENCE')
)
COMMENT '
Description
-----------
Tests whether the table specified in in_db and in_table exists either as a regular
table, or as a temporary table. The returned value corresponds to the table that
will be used, so if there''s both a temporary and a permanent table with the given
name, then ''TEMPORARY'' will be returned.
Parameters
-----------
in_db (VARCHAR(64)):
The database name to check for the existence of the table in.
in_table (VARCHAR(64)):
The name of the table to check the existence of.
out_exists ENUM('''', ''BASE TABLE'', ''VIEW'', ''TEMPORARY'', ''SEQUENCE'', ''SYSTEM VIEW'', ''TEMPORARY SEQUENCE''):
The return value: whether the table exists. The value is one of:
* '''' - the table does not exist neither as a base table, view, sequence nor temporary table/sequence.
* ''BASE TABLE'' - the table name exists as a permanent base table table.
* ''VIEW'' - the table name exists as a view.
* ''TEMPORARY'' - the table name exists as a temporary table.
* ''SEQUENCE'' - the table name exists as a sequence.
* ''SYSTEM VIEW'' - the table name exists as a system view.
* ''TEMPORARY SEQUENCE'' - the table name exists as a temporary sequence.
Example
--------
MariaDB [sys]> CREATE DATABASE db1;
Query OK, 1 row affected (0.07 sec)
MariaDB [sys]> use db1;
Database changed
MariaDB [sys]> CREATE TABLE t1 (id INT PRIMARY KEY);
Query OK, 0 rows affected (0.08 sec)
MariaDB [sys]> CREATE TABLE t2 (id INT PRIMARY KEY);
Query OK, 0 rows affected (0.08 sec)
MariaDB [sys]> CREATE view v_t1 AS SELECT * FROM t1;
Query OK, 0 rows affected (0.00 sec)
MariaDB [sys]> CREATE TEMPORARY TABLE t1 (id INT PRIMARY KEY);
Query OK, 0 rows affected (0.00 sec)
MariaDB [sys]> CREATE SEQUENCE s;
Query OK, 0 rows affected (0.00 sec)
MariaDB [sys]> CREATE TEMPORARY SEQUENCE s_temp;
Query OK, 0 rows affected (0.00 sec)
MariaDB [sys]> CALL sys.table_exists(''db1'', ''t1'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.00 sec)
+------------+
| @exists |
+------------+
| TEMPORARY |
+------------+
1 row in set (0.00 sec)
MariaDB [sys]> CALL sys.table_exists(''db1'', ''t2'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.00 sec)
+------------+
| @exists |
+------------+
| BASE TABLE |
+------------+
1 row in set (0.01 sec)
MariaDB [sys]> CALL sys.table_exists(''db1'', ''v_t1'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.00 sec)
+---------+
| @exists |
+---------+
| VIEW |
+---------+
1 row in set (0.00 sec)
MariaDB [sys]> CALL sys.table_exists(''db1'', ''s'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.006 sec)
+----------+
| @exists |
+----------+
| SEQUENCE |
+----------+
1 row in set (0.000 sec)
MariaDB [sys]> CALL table_exists(''information_schema'', ''user_variables'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.003 sec)
+-------------+
| @exists |
+-------------+
| SYSTEM VIEW |
+-------------+
1 row in set (0.001 sec)
MariaDB [sys]> CALL sys.table_exists(''db1'', ''t3'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.01 sec)
+---------+
| @exists |
+---------+
| |
+---------+
1 row in set (0.00 sec)
MariaDB [sys]> CALL table_exists(''db1'', ''s_temp'', @exists); SELECT @exists;
Query OK, 0 rows affected (0.003 sec)
+--------------------+
| @exists |
+--------------------+
| TEMPORARY SEQUENCE |
+--------------------+
1 row in set (0.001 sec)
'
SQL SECURITY INVOKER
NOT DETERMINISTIC
CONTAINS SQL
BEGIN
DECLARE v_error BOOLEAN DEFAULT FALSE;
DECLARE db_quoted VARCHAR(64);
DECLARE table_quoted VARCHAR(64);
DECLARE v_table_type VARCHAR(30) DEFAULT '';
DECLARE CONTINUE HANDLER FOR 1050 SET v_error = TRUE;
DECLARE CONTINUE HANDLER FOR 1146 SET v_error = TRUE;
-- First check do we have multiple rows, what can happen if temporary table
-- and/or sequence is shadowing base table for example.
-- In such scenario return temporary.
SET v_table_type = (SELECT GROUP_CONCAT(TABLE_TYPE) FROM information_schema.TABLES WHERE
TABLE_SCHEMA = in_db AND TABLE_NAME = in_table);
IF v_table_type LIKE '%,%' THEN
SET out_exists = 'TEMPORARY';
ELSE
IF v_table_type is NULL
THEN
SET v_table_type='';
END IF;
-- Don't fail on table_type='SYSTEM VERSIONED'
-- but return 'BASE TABLE' for compatibility with existing tooling
IF v_table_type = 'SYSTEM VERSIONED' THEN
SET out_exists = 'BASE TABLE';
ELSE
SET out_exists = v_table_type;
END IF;
END IF;
END$$
DELIMITER ;
|
