join on sub query returns fails

Trying to join a table "fab_qouta.qoutatype" to at value inside a sub query "fab_status_members.statustype" but it returns nothing.

If I join the 2 tables directly in a query the result is correct.

Like this:

select statustype, takst 
from   
  fab_status_members AS sm
    join fab_quota as fq
      ON fq.quotatype = sm.statustype

So I must be doing something wrong, here the sub query code, any help appreciated

select
  ju.id,
  name,
  statustype,
  takst

from jos_users AS ju 
  join 
  开发者_如何学运维  ( SELECT sm.Members AS MemberId, MaxDate , st.statustype 
      FROM fab_status_type AS st
        JOIN fab_status_members AS sm 
          ON (st.id = sm.statustype) -- tabels are joined 
        JOIN 
          ( SELECT members, MAX(pr_dato) AS MaxDate -- choose members and Maxdate from
            FROM fab_status_members 
            WHERE pr_dato <= '2011-07-01' 
            GROUP BY members
          )
          AS sq
          ON (sm.members = sq.members AND sm.pr_dato = sq.MaxDate)
     ) as TT
     ON ju.id = TT.Memberid
  join fab_quota as fq 
    ON fq.quotatype = TT.statustype 
GROUP BY id

Guess the problem is in the line: join fab_quota as fq ON fq.quotatype = TT.statustype

But I can't seem to look through it :-(

Best regards

Thomas

It looks like you are joining down to the lowest combination of per member with their respective maximum pr_dato value for given date. I would pull THIS to the FIRST query position instead of being buried, then re-join it to the rest...

select STRAIGHT_JOIN
      ju.id,
      ju.name,
      fst.statustype,
      takst
   from 
      ( SELECT 
              members, 
              MAX(pr_dato) AS MaxDate
           FROM 
              fab_status_members 
           WHERE 
              pr_dato <= '2011-07-01' 
           GROUP BY 
              members ) MaxDatePerMember

      JOIN jos_users ju
         on MaxDatePerMember.members = ju.ID

      JOIN fab_status_members fsm
         on MaxDatePerMember.members = fsm.members
        AND MaxDatePerMember.MaxDate = fsm.pr_dato

         JOIN fab_status_type fst
            on fsm.statustype = fst.id

            JOIN fab_quota as fq
               on fst.statusType = fq.quotaType

I THINK I have all of what you want, and let me reiterate in simple words what I think you want. Each member can have multiple status entries (via Fab_Status_Members). You are looking for all members and what their MOST RECENT Status is as of a particular date. This is the first query.

From that, whatever users qualify, I'm joining to the user table to get their name info (first join).

Now, back to the complex part. From the first query that determined the most recent date status activity, re-join back to that same table (fab_status_members) and get the actual status code SPECIFIC to the last status date for that member (second join).

From the result of getting the correct STATUS per Member on the max date, you need to get the TYPE of status that code represented (third join to fab_status_type).

And finally, from knowing the fab_status_type, what is its quota type.

You shouldn't need the group by since the first query is grouped by the members ID and will return a single entry per person (UNLESS... its possible to have multiple status types in the same day in the fab_status_members table... unless that is a full date/time field, then you are ok)

Not sure of the "takst" column which table that comes from, but I try to completely qualify the table names (or aliases) they are coming from, buy my guess is its coming from the QuotaType table.

... EDIT from comment...

Sorry, yeah, FQ for the last join. As for it not returning any rows, I would try them one at a time and see where the break is... I would start one at a time... how many from the maxdate query, then add the join to users to make sure same record count returned. Then add the FSM (re-join) for specific member / date activity, THEN into the status type... somewhere along the chain its missing, and the only thing I can think of is a miss on the status type as any member status would have to be associated with one of the users, and it should find back to itself as that's where the max date originated from. I'm GUESSING its somewhere on the join to the status type or the quota.