我需要使用来自外表的外键列(例如:fk_Price ID)的主表列(例如:Price)的总和
select sum(tbl_equipments.Price)来自tbl_equipments的价格,tbl_Lead其中tbl_Lead.fk_PriceId = tbl_equipments.Id
似乎你在tbl_Equipments
的每一行中保持tbl_Lead
的id两次,
对于列fk_ProductsID
和fk_PriceID
,
所以加入表并得到总和:
select sum(l.Price) Price
from tbl_Lead l inner join tbl_Equipments e
on e.id = l.fk_PriceID