Question

What I have:

I have a column in my table called privileges that stores a string of privileges for a user. (-1 = owner, 0 = admin, 1 = moderate comments, etc.) So I would have string like this in sql: 1,2,3.

The problem:

If I wanted to select all users that are admins AND moderators, it becomes a little tricky with LIKE conditions. Right now, If I want an admin, I just cycle through all the users search for 1 (using PHP – inefficient).

I am looking for a solution that is easily ‘plugged’ by plugin developers and is easily query-ed. My solution works, but if the users were to grow to hundreds, it could take awhile cycling through all them repeatedly just to find a certain privilege.

Does anyone have a better method or thoughts on this?

Answer 1

SELECT  *
FROM    privileges
WHERE   FIND_IN_SET(0, privilege)
        AND FIND_IN_SET(1, privilege)

You will have a faster query if you normalize your table (create an additional table user_privileges with separate record per privilege). This way you could run:

SELECT  user
FROM    user_privileges
WHERE   privilege IN (0, 1)
GROUP BY
        user
HAVING  COUNT(*) = 2

and this could use an index on privilege.

You may also consider storing the privileges in a native SET datatype.