mysql - 如何在WHERE CLAUSE中使用DISTINCT以避免重复的行返回

此SQL查询的结果应返回一组6行。

SELECT baseFeeds.siteURL, feedFinishes.timeTaken, feedFinishes.timeSubmitted
FROM feedFinishes
LEFT OUTER JOIN baseFeeds
ON feedFinishes.GUID = baseFeeds.GUID
WHERE feedFinishes.nowDate = baseFeeds.nowDate
AND baseFeeds.siteURL LIKE '%www.example.com%'

目前它返回18行，正确的6行被重复3次。我想解决这个问题的办法是使用另一个where子句，类似于：
WHERE DISTINCT feedFinishes.ID
经过研究，我尝试过：

SELECT baseFeeds.siteURL, feedFinishes.timeTaken, feedFinishes.timeSubmitted
FROM feedFinishes
JOIN baseFeeds
ON feedFinishes.GUID = baseFeeds.GUID
WHERE baseFeeds.siteURL LIKE '%www.example.com%' AND feedFinishes.ID in
     (SELECT ID FROM feedFinishes GROUP BY ID HAVING COUNT(ID)=1);

讨论后发现here
唉，这仍然返回18行。我相信答案与here
任何建议都将不胜感激。

最佳答案

你应该适用group by条款。

SELECT
baseFeeds.siteURL, feedFinishes.timeTaken, feedFinishes.timeSubmitted
FROM feedFinishes
JOIN baseFeeds
ON feedFinishes.GUID = baseFeeds.GUID
WHERE baseFeeds.siteURL LIKE '%www.example.com%'
GROUP BY
baseFeeds.siteURL, feedFinishes.timeTaken, feedFinishes.timeSubmitted