SQL Search list for value

Question

Hello all,
I am trying to search a huge table of users to see if they
belong to a certain group. The group field would be as follows:
group_id = 1,2,4,7
In the interest of server memory, I do not want to pull the
entire table and search with CF (listfind). Instead, I would like
to run an SQL query like this:
Select *
FROM table
where group_id CONTAINS '2'
Of course I can't do this. I'm a liitle rusty on my SQL.
Could someone help??
Thanks

Answer 1

MySQL may have functions that allow you to find a value in a
list. If not you may need to use a series LIKE statements. Either
way the query will almost certainly be slower than if your data
were properly normalized.
Field = '2' OR Field LIKE '2,%' OR Field LIKE '%,2,%' OR
Field LIKE '%,2'
Storing data in that manner is generally considered a bad
design. One of the reasons is what you've discovered: its difficult
to query. I would strongly recommend that you normalize your data.
User Table: UserID, UserName, ...
Group Table: GroupID, GroupName, ...
UserGroup Table:
UserID | GroupID
1 | 20
1 | 2
1 | 4
1 | 7
3 | 20
3 | 89
3 | 22
5 | 122
Your query would be simply
SELECT UserID
FROM UserGroup
WHERE GroupID = 2