兩表聯(lián)查sql語句 sql多對(duì)多查詢?
sql多對(duì)多查詢?好幾種寫法,我這里就寫一個(gè)算拋磚引玉吧,也算給你一個(gè)提示。selectnamefromawhereidin(selectc.aidfromcwherebinin(selectidfr
sql多對(duì)多查詢?
好幾種寫法,我這里就寫一個(gè)算拋磚引玉吧,也算給你一個(gè)提示。selectnamefromawhereidin(selectc.aidfromcwherebinin(selectidfrombwherejobin("q","r")))也可以直接關(guān)聯(lián)到c表然后相等,這個(gè)辦法應(yīng)該不錯(cuò),可以直接對(duì)應(yīng)。
sql語句多對(duì)多查詢?
select * from book a join (select cid,count(1) as [count] from category group by cid) b where a.id=b.cid