mysql篩選條件執行順序

from on join where group by having select distinct union order by 這個順序實際上是很重要，用的好可以提高你的查詢效率，好比說如下語句web 1：select A.ID as AID, B.ID as BID from A left join B on A.ID = B.ID where B.ID<

>>阅读原文<<