Question

sql 表A表B通过表C关联 怎么把表B里的值添加到表A

select a.bby29,c.iah25 from bby1 a
left join iam1 b on a.bby01=b.bby01
left join iah1 c on b.iah01=c.iah01
where b.iaa01=470 and c.iaa01=470

请问如何把iah25添加bby29

Answer 1

update bby1 a set bby29 =( select c.iah25 from bby1 a
left join iam1 b on a.bby01=b.bby01
left join iah1 c on b.iah01=c.iah01
where b.iaa01=470 and c.iaa01=470)