通过外键列获取多行

Question

我有一个包含多个地址的地址 table

Address: 
| Id   |   details   | ... |  
 - - - - - - - - -  - - - - - - - 
| 1    |  details |    ...        |
| 2    |  details |    ...        |
| 3    |  details |    ...        |
| 4    |  details |    ...        |

然后我有一个站点 table，其中包含 address.id 作为代表帐单或送货地址的 FK，

Site: 
| Id   |   details   | Ship_Address_id  |  Bill_Address_id | ... |
 - - - - - - - - -  - - - - - - - 
| 1    |  details |          1           |        2          |     |
| 2    |  details |          1           |        3          |     |  
| 3    |  details |          4           |        4          |     |
| 4    |  details |          2           |        3          |     |

有没有办法连接两个 table 以便来自站点 table 的单行可以获取地址 table 的两行，即使是在地址相同的情况下两列。我期待使用地址的多个站点连接，但这不起作用：

这是我试过的：

SELECT CASE 
        WHEN ship.CRM_Address_Internal_Id_Ship IS NOT NULL THEN 'Ship'
        WHEN bill.CRM_Address_Internal_Id_Ship IS NOT NULL THEN 'Bill'
        ELSE '' END 
FROM Address as Adr
LEFT JOIN Site ship ON ship.Ship_Address_id = Adr.id 
LEFT JOIN Site bill ON bill.Bill_Address_id = Adr.id

即使我不使用 CASE，它也不会为站点的每个地址获取两行。

请指教。

编辑这是所需的输出 table：与站点 table 一样，我们有两个不同的地址 ID table (Ship/Bill) 因此结果 table 应该为每个 site.id[=29= 显示两行] 例如，我正在获取 site.id 1 和 3 的记录，然后

Result_Table:
| Address.ID | Address Details | TYPE | ... |
--------------------------------------------
| 1         | Other Details    | Ship | ... |
| 2         | Other Details    | Bill | ... |
| 4         | Other Details    | Ship | ... |
| 4         | Other Details    | Bill | ... |

Answer 1

有多种方法可以做到这一点。这是我用UNPIVOT实现的一个例子，大家可以参考一下：

declare @address table(id int, details nvarchar(100))
declare @site table(id int, details nvarchar(100), ship_address_id int, bill_address_id int)

insert into @address values(1,'details 1')
insert into @address values(2,'details 2')
insert into @address values(3,'details 3')
insert into @address values(4,'details 4')

insert into @site values(1,'details 1',1,2)
insert into @site values(2,'details 1',1,3)
insert into @site values(3,'details 1',4,4)
insert into @site values(4,'details 1',2,5)


SELECT * 
FROM (
    SELECT s.id as site_id, s.bill_address_id, s.ship_address_id
    FROM @Site AS s
    INNER JOIN @Address AS sa ON s.Ship_Address_id = sa.Id
    INNER JOIN @Address AS ba ON s.Bill_Address_id = ba.Id
    WHERE s.id in (1,3)) p
UNPIVOT 
     (address_id FOR address_type IN 
      (Ship_Address_id, Bill_Address_id)
) AS unpvt

输出

site_id     address_id  address_type
1           1           ship_address_id
1           2           bill_address_id
3           4           ship_address_id
3           4           bill_address_id

Answer 2

您似乎在寻找 UNION ALL，而且您的表格是倒着的。我认为您正在寻找更像这样的东西：

SELECT ship.id Site_id, CASE 
        WHEN ship.CRM_Address_Internal_Id_Ship IS NOT NULL THEN 'Ship'
        ELSE 'No Ship' END AddressPresent
FROM Site ship
LEFT JOIN Address Adr ON ship.Ship_Address_id = Adr.id

UNION ALL

SELECT bill.id Site_id, CASE 
        WHEN bill.CRM_Address_Internal_Id_Ship IS NOT NULL THEN 'Bill'
        ELSE 'No Bill' END AddressPresent
FROM Site bill
LEFT JOIN Address Adr ON bill.Bill_Address_id = Adr.id

我还想知道您是否有 'CRM_Address_Internal_Id_Bill' 列应该在查询的第二部分？

通过外键列获取多行

Fetching multiple rows by foreign key column

sql-server

join

self-join