MySQL 5.5.32 Schema Setup:
CREATE TABLE list
(`id` int, `list` varchar(5))
;
INSERT INTO list
(`id`, `list`)
VALUES
(1, '1,2,3'),
(2, '6,8')
;
CREATE TABLE user
(`id` int, `name` varchar(4))
;
INSERT INTO user
(`id`, `name`)
VALUES
(1, 'jack'),
(2, 'john'),
(3, 'jane'),
(6, 'jim'),
(8, 'jade')
;
Query 1:
SELECT (SELECT GROUP_CONCAT(user.name)
FROM user WHERE instr(concat(' ,',list.list,','),concat(',',user.id,',')) > 1
)
FROM list
jack,john,jane
jim,jade