Stored procedure, using variable in LIMIT expression

Question

I have a stored procedure in which if I write the following query without a variable, all: works well

 CREATE PROCEDURE `some_proc` ()
 BEGIN
 SELECT blabla FROM  mytable ORDER BY id LIMIT 3,1
 .....

but, if I use a variable as start number in LIMIT expression, I get an error:

 CREATE PROCEDURE `some_proc` ()
 BEGIN
 DECLARE start INT;
 SET start = 3;
 SELECT blabla FROM  mytable ORDER BY id LIMIT start,1
 .....

Is there a way to use a variable in the LIMIT expression inside the stored procedure?

Answer 1

You cannot use a variable directly. A nice workaround that I've seen is -

CREATE PROCEDURE `some_proc` (
IN _START INTEGER, 
IN _LIMIT INTEGER 
)
BEGIN 
PREPARE STMT FROM 
" SELECT * FROM products LIMIT ?,? "; 
SET @START = _START; 
SET @LIMIT = _LIMIT; 
EXECUTE STMT USING @START, @LIMIT;
DEALLOCATE PREPARE STMT;
END $$ 

Another search returned this - http://bugs.mysql.com/bug.php?id=8094.

Also you can read more about prepared statements in the manual.