select distinct base.Id from ProDataBasic base join ProIntroduction intro on intro.Pro_Id = base.Id where T_Status=3 order by base.Id desc
能去重复
多加了几个字段之后就不能去重复了
select distinct base.Id,T_Name,T_Type,T_Cover,T_Businesses,intro.IContent from ProDataBasic base join ProIntroduction intro on intro.Pro_Id = base.Id order by base.Id desc为什么呢?
能去重复
多加了几个字段之后就不能去重复了
select distinct base.Id,T_Name,T_Type,T_Cover,T_Businesses,intro.IContent from ProDataBasic base join ProIntroduction intro on intro.Pro_Id = base.Id order by base.Id desc为什么呢?
id ,name
1,a
1,b那么select distinct id from tb 是只有一条,但是select distinct * 就会有两条,这个应该好理解吧。当你有多个字段的时候,必须“同时”重复,才会去除重复。