Question

Table A

id    name
1     name1
2     name2
3     name3
4     name4

Table B

id    userlist
1     1,2,3,4

What I do now is

SELECT `userlist` FROM `table B` WHERE `id` = 1

Then save the result and put into second query

SELECT `name` FROM `table A` WHERE `id` in ($userlist)

Just wondering if got better way. I try

SELECT `name` FROM `table A` WHERE `id` in (SELECT `userlist` FROM `table B` WHERE `table B`.`id` = 1)

But it only return 1 result.

EDIT*

DB structure can not be change since so many data inside. I just try to optimize the old code.

Answer 1

You could use FIND_IN_SET:

SELECT `name`
FROM `table A` INNER JOIN `table B` ON
     FIND_IN_SET(`table A`.`id`, `table B`.`userlist`)
WHERE `table B`.`id` = 1

but i would suggest you to normalize your tables.