嵌套更新|更新产品所对应的公司分类
update ProContent set Fid=(select Fid from companys where C_ID=ProContent.C_ID),Sid=(select Sid from companys where C_ID=ProContent.C_ID),Tid=(select Tid from companys where C_ID=ProContent.C_ID) where Fid is null
嵌套更新|更新产品所对应的公司分类
update ProContent set Fid=(select Fid from companys where C_ID=ProContent.C_ID),Sid=(select Sid from companys where C_ID=ProContent.C_ID),Tid=(select Tid from companys where C_ID=ProContent.C_ID) where Fid is null