Question

i just want limit a query by parameter inside a stored, but I get an error in the LIMIT field:

DELIMITER //
DROP FUNCTION IF EXISTS test//
CREATE PROCEDURE test(lim INT)
  BEGIN
    SELECT * FROM logs LIMIT 0,lim; 
  END //
DELIMITER ;

What I miss?

Answer 1

MySQL LIMIT clause has some limitations. Refer to a known bug id=11918 here.

This isn’t specific to stored routines.
LIMIT doesn’t allow variables in any context.
Its arguments must be integer constants.

A workaround is using prepared statements in stored procedures.

Example:

mysql> DROP PROCEDURE IF EXISTS names_proc;
Query OK, 0 rows affected (0.00 sec)

mysql> DELIMITER //
mysql> CREATE PROCEDURE names_proc( lim INT )
    ->   BEGIN
    ->     PREPARE STMT FROM 'SELECT * FROM names LIMIT 0, ?';
    ->     EXECUTE STMT USING @lim;
    ->   END;
    -> //
Query OK, 0 rows affected (0.00 sec)

mysql> DELIMITER ;
mysql> CALL names_proc( 3 );
+------+----------+
| id   | name     |
+------+----------+
|    1 | jimjoe   |
|    2 | jimddjoe |
|    3 | jim      |
+------+----------+
3 rows in set (0.00 sec)

Query OK, 0 rows affected (0.01 sec)