表一:ryxx
class,ry_id,ry_name
a,1,zhangsan
a,2,lisi
a,3,wangwu
b,4,maliu
表二:ry_gz
ry_id,ry_gz
1,3000
3,3200
1,1200
想得到的结果查询是:
class,ry_id,ry_name,ry_gz
a,1,zhangsan,4200(即3000+1200)
a,2,lisi,0(或null)
a,3,wangwu,3200
b,4,maliu,0(或null)请问视图查询如何写,求助
class,ry_id,ry_name
a,1,zhangsan
a,2,lisi
a,3,wangwu
b,4,maliu
表二:ry_gz
ry_id,ry_gz
1,3000
3,3200
1,1200
想得到的结果查询是:
class,ry_id,ry_name,ry_gz
a,1,zhangsan,4200(即3000+1200)
a,2,lisi,0(或null)
a,3,wangwu,3200
b,4,maliu,0(或null)请问视图查询如何写,求助
多了一个列名
from ryxx a left join
(select ry_id,sum(ry_gz) as gz from ry_gz group by ry_id) b
on a.ry_id=b.ry_id
order by a.class,a.ry_id