COUNTing GROUPed是多少行？

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`)

我有一个类似于此的查询，显然AND COUNT(lsa)=6位不是有效的语法。我很迷茫。

我想要实现的是一个列表，由lsa和排序，按uid分组，只有当该uid有6个条目时，即在“组”中。我该怎么做？

Answer 1

按聚合进行筛选是有效的，但需要进入HAVING子句，而不是使用WHERE。

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`)  

而不是。