MySQL problem: select a user where membergroupids = 5,7

[Yurimien]

I want to select a list of users that have a certain membergroupid

SELECT username
FROM vb_user
WHERE membergroupids = '9'
LIMIT 0 , 30

The code works when the user only has one additional group assigned, but most of my users have 5 groups assigned. The content in the database looks like: 5,7,9,10
So how can I make sure I also select those with multiple usergroups?

--------------- Added [DATE]1201523929[/DATE] at [TIME]1201523929[/TIME] ---------------
@the one that posted a reply earlier:
This selects it only if the membergroupids start with 5. But it helped me, I've added everyone to the registered members group, and expanded it to
WHERE membergroupids IN (2 , 5 , 7 )


Thank you.

[Eikinskjaldi]

That still isn't going to help you when the membergroupids is more than one. The mysql function you want is find_in_set

[mysql]
select username from user where find_in_set('9',membergroupids)
[/mysql]

The main issue is this query is in no way optimised to use indices, and will do a full table scan.

[petteyg359]

What is the difference between find_in_set and this:

SELECT username
FROM vb_user
WHERE membergroupids LIKE '%9%'
LIMIT 0, 30

[MoT3rror]

You are going to get 29, 92, etc.