mariadb/scripts/sys_schema/functions/list_drop.sql

91 lines
3.5 KiB
SQL

-- 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 FUNCTION IF EXISTS list_drop;
DELIMITER $$
CREATE DEFINER='mariadb.sys'@'localhost' FUNCTION list_drop (
in_list TEXT,
in_drop_value TEXT
)
RETURNS TEXT
COMMENT '
Description
-----------
Takes a list, and a value to attempt to remove from the list, and returns the resulting list.
Useful for altering certain session variables, like sql_mode or optimizer_switch for instance.
Parameters
-----------
in_list (TEXT):
The comma separated list to drop a value from
in_drop_value (TEXT):
The value to drop from the input list
Returns
-----------
TEXT
Example
--------
mysql> select @@sql_mode;
+-----------------------------------------------------------------------------------------------+
| @@sql_mode |
+-----------------------------------------------------------------------------------------------+
| ANSI_QUOTES,ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION |
+-----------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> set sql_mode = sys.list_drop(@@sql_mode, ''ONLY_FULL_GROUP_BY'');
Query OK, 0 rows affected (0.03 sec)
mysql> select @@sql_mode;
+----------------------------------------------------------------------------+
| @@sql_mode |
+----------------------------------------------------------------------------+
| ANSI_QUOTES,STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION |
+----------------------------------------------------------------------------+
1 row in set (0.00 sec)
'
SQL SECURITY INVOKER
DETERMINISTIC
CONTAINS SQL
BEGIN
IF (in_drop_value IS NULL) THEN
SIGNAL SQLSTATE '02200'
SET MESSAGE_TEXT = 'Function sys.list_drop: in_drop_value input variable should not be NULL',
MYSQL_ERRNO = 1138;
END IF;
IF (in_list IS NULL OR LENGTH(in_list) = 0) THEN
-- return the list as it was passed in
RETURN in_list;
END IF;
-- ensure that leading / trailing commas are remove, support values with either spaces or not between commas
RETURN (SELECT TRIM(BOTH ',' FROM REPLACE(REPLACE(CONCAT(',', in_list), CONCAT(',', in_drop_value), ''), CONCAT(', ', in_drop_value), '')));
END$$
DELIMITER ;