DROP TABLE IF EXISTS MyTable2 CASCADE;

​

CREATE TABLE MyTable2

    (`p_id` int, `p_name` varchar(8), `c_id` varchar(6))

;

INSERT INTO MyTable2

    (`p_id`, `p_name`, `c_id`)

VALUES

    (1, 'Product1', '1'),

    (2, 'Product2', '2,3,4'),

    (2, 'Product3', '1,2')

;

​

SELECT @search_id := 1;

​

 SELECT *

 FROM MyTable2

 WHERE CONCAT(',' , c_id, ',') like CONCAT('%,', @search_id, ',%')