Question

SELECT id,name,SUM(`lsa`) AS lst FROM 
    table_a AS sn,
    table_b AS fb 
WHERE sn.uid=fb.uid 
  AND COUNT(`lsa`)=6 
GROUP BY sn.uid 
ORDER BY SUM(`lsa`)

I have a query like this one, apparently the AND COUNT(lsa)=6 bit isn’t valid syntax. I’m quite lost.

What I’d like to achieve is a list, ordered by the sum of lsa, grouped by uid, only if there are 6 entries for that uid, i.e. in that “group”. How am I supposed to do that?

Answer 1

It is valid to filter by aggregates but that needs to go into the HAVING clause, not the WHERE so use

SELECT id,
       name,
       SUM(`lsa`) AS lst
FROM   table_a AS sn
       JOIN table_b AS fb
         ON sn.uid = fb.uid  /*Using Explicit Join syntax*/
GROUP  BY sn.uid,            /*And avoiding MySQL GROUP BY extension*/
          id,
          name
HAVING COUNT(`lsa`) = 6
ORDER  BY SUM(`lsa`)  

instead.