SQL一對多特殊查詢，取唯一一條

主表：

輔表：

一個app對應多個apk，現在要取上線(Apk_Status最大的)的應用

select * from [dbo].[tbl_APP] as app 
join 

(select * from [dbo].[tbl_Apk] as AA where not exists(select top 1 * from tbl_Apk as BB where AA.Apk_APPId=BB.Apk_APPId and AA.Apk_Status < BB.Apk_Status))

 as apk on app.APP_Id = apk.Apk_APPId

重點是取關聯的右表：

select * from [dbo].[tbl_Apk] as AA where not exists(select top 1 * from tbl_Apk as BB where AA.Apk_APPId=BB.Apk_APPId and AA.Apk_Status < BB.Apk_Status)

沒看懂這個not exists的邏輯 ～～