Query IN() not working as intended

If I run the query:

SELECT board.id, board.name
FROM board
INNER JOIN group_assoc ON group_id
IN (
"4,9,12,15,18,21,22,55,57,83,84,86,89,92,95,98,104,105"
)
AND group_assoc.board_id = bo开发者_StackOverflow中文版ard.id
INNER JOIN category ON category.id = board.category_id
AND category.forum_id =2

I get a different result than

SELECT board.id, board.name
FROM board
INNER JOIN group_assoc ON group_id = 9
AND group_assoc.board_id = board.id
INNER JOIN category ON category.id = board.category_id
AND category.forum_id =2

Is it only pulling boards that can be viewed by all groups?

---

If the values in "IN" are integers, don't use double quotation marks (" "), like this

SELECT board.id, board.name
FROM board
INNER JOIN group_assoc ON group_id
IN (
4,9,12,15,18,21,22,55,57,83,84,86,89,92,95,98,104,105
)
AND group_assoc.board_id = board.id
INNER JOIN category ON category.id = board.category_id
AND category.forum_id =2

And if the values are strings, use double quotation marks for each string.

SELECT board.id, board.name
FROM board
INNER JOIN group_assoc ON group_id
IN (
"4121213","9434345443","12545454"
)
AND group_assoc.board_id = board.id
INNER JOIN category ON category.id = board.category_id
AND category.forum_id =2

---

Try IN (4,9,12,...)