Select
b.定单编号,sum(c.购买数量*a.产品价格) as 总金额
From
产品表 a, 订单表 b, 订单明细表 c
Where
a.产品编号 = c.产品编号 And b.定单编号 = c.定单编号
Group by
b.定单编号
b.定单编号,sum(c.购买数量*a.产品价格) as 总金额
From
产品表 a, 订单表 b, 订单明细表 c
Where
a.产品编号 = c.产品编号 And b.定单编号 = c.定单编号
Group by
b.定单编号
a.定单编号,sum(b.购买数量*a.产品价格) as 总金额
From
产品表 a join 订单明细表 b
on
a.产品编号 = b.产品编号
Group by
a.定单编号
a.定单编号,sum(a.购买数量*b.产品价格) as 总金额
From 订单明细表 a
left join 产品表 b
on a.产品编号 = b.产品编号
Group by
a.定单编号