MySQL: Using variable on a WHERE IN clause

I'm becoming mad trying to use an "array" of values obtained from a GROUP_CONCAT into a WHERE IN statement, when GROUP_CONCAT only takes one "id" it works ok but when it takes more it doesn't.

As it follows:

START TRANSACTION;
DECLARE @coupon_ids VARCHAR(MAX);
-- Take one or more ids
开发者_开发百科SET @coupon_ids:=(SELECT IFNULL( (SELECT GROUP_CONCAT(coupon_id) FROM some_table WHERE order_id=(SELECT entity_id FROM sales_order WHERE increment_id=310033638) GROUP BY order_id),  (SELECT coupon_id FROM some_table WHERE coupon_id=310033638)));
SELECT @coupon_ids;
INSERT INTO some_table_gift VALUES (NULL,TRIM('whatever'),'','');
SET @lastid:=LAST_INSERT_ID();
-- Here if @coupon_ids is just one id, like 123 it works, if it is a list of them like 123,234,254 it doesn't works
UPDATE some_table SET owner_id=@lastid,is_gift=1 WHERE coupon_id IN (@coupon_ids);
COMMIT;
-- Same here
SELECT coupon_id,owner_id,is_gift FROM some_table WHERE coupon_id IN (@coupon_ids);

Does anyone know how to work with this?

Thanks!

What's your filed type for coupon_id, if it is not any number type than it will not work.

One way you can add quote (single quote) for each result in GROUP_CONCAT Write

GROUP_CONCAT(coupon_id SEPARATOR '","')

remove SELECT @coupon_ids

And

in QUERY try this WHERE coupon_id IN ("@coupon_ids")