Mysql group by 和 having with max 值不返回实际最大值

Question

SELECT c.testid, t.testid, c.studyid, c.PRINCIPAL, t.buildnumber 
FROM comp_max c
INNER JOIN testlog t
ON t.testid = c.testid
WHERE t.buildnumber = 1030716
ORDER BY studyid ASC

结果

testid  testid  studyid PRINCIPAL   buildnumber
403      403    1109    2670506       1030716
497      497    1109    2468736       1030716
**495        495    1109    2468736       1030716**
442      442    1109    2468736       1030716

所以我尝试了下面的查询来获取最大 testid (495)

SELECT c.testid, t.testid, c.studyid, c.PRINCIPAL, t.buildnumber 
FROM comp_max c
INNER JOIN testlog t
ON t.testid = c.testid
WHERE t.buildnumber = 1030716
group by studyid having max(c.testid)

但是返回值是403 testid，不是495

testid  testid  studyid PRINCIPAL   buildnumber
403      403    1109    2670506       1030716

因此预期结果将是 testid 495。有人能帮我解决这个问题吗？或任何提示？

谢谢

Answer 1

我自己使用子查询解决了问题 这是答案

SELECT c.studyid, c.testid, c.PRINCIPAL FROM comp_max c 
WHERE c.testid in (
   SELECT MAX(c.testid) FROM comp_max c
   INNER JOIN testlog t ON t.testid = c.testid
   WHERE c.studyid IN ( 
                    SELECT c.studyid FROM comp_max c 
                    INNER JOIN testlog t
                    ON t.testid = c.testid
                    WHERE t.buildnumber = 1030716 )
   AND t.buildnumber = 1030716
   GROUP  BY c.studyid )
GROUP BY studyid
ORDER BY c.studyid desc

如果您有更好的解决方案，我非常乐意得到您的答复 谢谢