Question

I’m going crazy on this hope someone can help me out….

I have one Table:

user_skils:
ID  | UID | SKILL
1     23    House
2     5    Disco
3     8    Punk
...  ...    ...
...  ...    ...
...  ...    ...

Now Im building a search query where the user can search and filter out people that don’t match the criteria:

Example Search: Disco, Punk, House

Meaning that I only want the users that match this 3 criterias ( have House AND Disco AND PUNK)…
How can I manage this via a query?

Something like

SELECT count(uid) as matches , 
  GROUP_CONCAT(skill) as skills_grouped 
FROM user_skilks 
WHERE skill LIKE %Disco% 
  AND skill LIKE %punk% 
  AND skill LIKE %house%

Should give me something like:

Matches | skills_grouped
3         House,Punk,Disco

Meaning that 3 people match this criteria…

Answer 1

Group your table by UID and then filter the resulting groups (i.e. using the HAVING clause) for those of interest:

SELECT   UID
FROM     user_skils
GROUP BY UID
HAVING   SUM(SKILL LIKE '%House%')
     AND SUM(SKILL LIKE '%Disco%')
     AND SUM(SKILL LIKE '%Punk%' )

This works in MySQL because it does not have true boolean types. In other RDBMS, you would have to use a CASE expression:

HAVING   SUM(CASE WHEN SKILL LIKE '%House%' THEN 1 ELSE 0 END) > 0
     AND ...

To get the number of such users, group the results again:

SELECT COUNT(*) FROM (
  SELECT   1
  FROM     user_skils
  GROUP BY UID
  HAVING   SUM(SKILL LIKE '%House%')
       AND SUM(SKILL LIKE '%Disco%')
       AND SUM(SKILL LIKE '%Punk%' )
) t