我尝试了一些方法，但似乎无法找出导致问题的原因。 当我删除 TotalHours 部分时，查询工作正常。但有了它，它会显示正确的小时数，但显示错误的职位、选定的和获胜者的数量。
有人可以告诉我我做错了什么吗？
提前致谢。
这是我的查询；
SELECT
crmCandidate.candidateID,
crmCandidate.candidateName,
COUNT(DISTINCT crmJoin.joinID) AS Jobs,
SUM(IF(crmJoin.joinExtra = 'select', 1, 0)) AS Selected,
SUM(IF(crmJoin.joinExtra = 'winner', 1, 0)) AS Winner,
ROUND(SUM(crmDays.total)) AS totalDays
FROM crmCandidate
LEFT JOIN crmJoin ON (crmJoin.joinChild = crmCandidate.candidateID)
LEFT JOIN crmJob ON (crmJob.jobID = crmJoin.joinParent)
LEFT JOIN crmDays ON (crmDays.dayCandidateID = crmJoin.joinChild)
WHERE
crmDays.dayJobID = crmJob.jobID AND
crmDays.dayCandidateID = crmCandidate.candidateID
GROUP BY
crmCandidate.candidateID
ORDER BY DESC
LIMIT 100
最佳答案
试试这个:
SELECT
crmCandidate.candidateID,
crmCandidate.candidateName,
COUNT(DISTINCT crmJoin.joinID) AS Jobs,
Sum(Case When crmJoin.joinExtra = 'select' Then 1 else 0 end) as Selected,
Sum(Case When crmJoin.joinExtra = 'winner' Then 1 else 0 end) as winner,
ROUND(SUM(crmDays.total)) AS totalDays
FROM crmCandidate
LEFT JOIN crmJoin
ON crmJoin.joinChild = crmCandidate.candidateID
LEFT JOIN crmJob
ON crmJob.jobID = crmJoin.joinParent
Inner JOIN crmDays
On crmDays.dayCandidateID = crmCandidate.candidateID
AND crmDays.dayJobID = crmJob.jobID
GROUP BY crmCandidate.candidateID, crmCandidate.candidateName
ORDER BY candidateID DESC
LIMIT 100
关于mysql - 查询中的 Count、SUM、LEFT JOIN 和 GROUP BY 无法正常工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26590792/