使用跨多个表的多个字段来连接表

Question

我想根据多个字段连接表，其中一个来自直接表，另一个来自邻接表。

我想加入的“装备”，以“合同细节”上ContractDetailID只有当设备客户id =合同客户ID。

Answer 1

declare @contract as table(
    contractid int, 
    customerid int 
) 

declare @contractDetail as table(
    contractDetailId int, 
    ContractID int 
) 

declare @equipment as table(
    equipmentId int, 
    contractDetailId int, 
    CustomerId int 
) 

insert into @contract values(5,3) 
insert into @contractDetail values(10,5) 
insert into @equipment values(1,10,3) 

select e.* 
from 
    @contract c inner join 
    @contractDetail cd on (c.contractId = cd.contractID) inner join 
    @equipment e on (c.customerId = e.CustomerId and e.contractDetailId = cd.contractDetailId)