10.4 9183f66f056e27490

MariaDB [test]> CREATE OR REPLACE FUNCTION func() RETURNS int RETURN   ( (SELECT 1 a) UNION (SELECT 2)  limit 1 );

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION (SELECT 2)  limit 1 )' at line 1

MariaDB [test]> (SELECT 1 a) UNION (SELECT 2)  limit 1;

+---+

| a |

+---+

| 1 |

+---+

1 row in set (0.001 sec)

MariaDB [test]> ((SELECT 1 a) UNION (SELECT 2)  limit 1);

+---+

| a |

+---+

| 1 |

| 2 |

+---+

2 rows in set (0.001 sec)

MariaDB [test]> ((SELECT 1 a) UNION (SELECT 2)  limit 1) limit 1;

+---+

| a |

+---+

| 1 |

+---+

1 row in set (0.002 sec)

MariaDB [test]> CREATE OR REPLACE FUNCTION func() RETURNS int RETURN   (( (SELECT 1 a) UNION (SELECT 2)  limit 1 )limit 1);

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION (SELECT 2)  limit 1 )limit 1)' at line 1

MariaDB [test]> (select 1 union select 1 union select 1);      

+---+

| 1 |

+---+

| 1 |

| 1 |

+---+

MariaDB [test]> explain extended (select 1 union select 1 union select 1);

+------+--------------+--------------+------+---------------+------+---------+------+------+----------+----------------+

| id   | select_type  | table        | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra          |

+------+--------------+--------------+------+---------------+------+---------+------+------+----------+----------------+

|    1 | PRIMARY      | NULL         | NULL | NULL          | NULL | NULL    | NULL | NULL |     NULL | No tables used |

|    2 | UNION        | NULL         | NULL | NULL          | NULL | NULL    | NULL | NULL |     NULL | No tables used |

|    3 | UNION        | NULL         | NULL | NULL          | NULL | NULL    | NULL | NULL |     NULL | No tables used |

| NULL | UNION RESULT | <union1,2,3> | ALL  | NULL          | NULL | NULL    | NULL | NULL |     NULL |                |

+------+--------------+--------------+------+---------------+------+---------+------+------+----------+----------------+

MariaDB [test]> show warnings;

+-------+------+--------------------------------------------------------------------------------------------------------------+

| Level | Code | Message                                                                                                      |

+-------+------+--------------------------------------------------------------------------------------------------------------+

| Note  | 1003 | /* select#1 */ select 1 AS `1` union /* select#2 */ select 1 AS `1` union all /* select#3 */ select 1 AS `1` |

+-------+------+--------------------------------------------------------------------------------------------------------------+