寻求查询方面的帮助。我有一个客户表记录客户链接到基本位置。以及详细说明特定时间点位置地址的位置表。
CREATE TABLE [dbo].[Customer](
[ID] [int] NULL,
[Date of Transfer] [datetime] NULL,
[Old Location] [int] NULL,
[New Location] [int] NULL)
INSERT INTO [dbo].[Customer] (ID, [Date of Transfer], [Old Location], [New Location])
VALUES (1, '2016-07-01 00:00:00.000', 1001, 2200),
(1, '2017-11-25 00:00:00.000', 2200, 3078),
(1, '2018-01-01 00:00:00.000', 3078, 8500),
(2, '2016-02-27 00:00:00.000', 5578, 9901),
(2, '2017-06-22 00:00:00.000', 9901, 9001);
CREATE TABLE [dbo].[Location](
[Location Code] [int] NULL,
[Location Address] [nvarchar](50) NULL,
[Date From] [date] NULL,
[Date To] [date] NULL)
INSERT INTO [dbo].[Location] ([Location Code], [Location Address], [Date From], [Date To])
VALUES (1001, 'Logan Street', '1998-02-01 00:00:00.000', '2017-07-21 00:00:00.000'),
(2200, 'Ashdown Avenue', '2014-01-31 00:00:00.000', NULL),
(3078, 'Chessington Court', '2009-05-11 00:00:00.000', '2018-03-30 00:00:00.000'),
(8500, 'Cambridge Green', '2018-01-15 00:00:00.000', '2018-02-15 00:00:00.000'),
(8500, 'Blair Road', '2018-02-15 00:00:00.000', NULL),
(5578, 'Aberdeen View', '2000-11-19 00:00:00.000', '2017-05-13 00:00:00.000'),
(9901, 'Tay Road', '2013-02-02 00:00:00.000', '2018-01-22 00:00:00.000'),
(9001, 'Wellington Way', '2015-02-16 00:00:00.000', '2018-02-22 00:00:00.000');
我试图加入两个表格，以便向我提供与客户相关联的位置的地址，这是他们转移到另一个位置的点。对于大多数人来说，使用以下
可以正常工作SELECT [ID]
,[Date of Transfer]
,[Old Location]
,O.[Location Address]
,O.[Date From]
,O.[Date To]
,[New Location]
,N.[Location Address]
,N.[Date From]
,N.[Date To]
FROM [dbo].[Customer]
Left Join [dbo].[Location] O on [Old Location] = O.[Location Code] and ([Date of Transfer] >= O.[Date From] OR O.[Date From] is NULL) and ([Date of Transfer] <= O.[Date To] or O.[Date To] is NULL)
Left Join [dbo].[Location] N on [New Location] = N.[Location Code] and ([Date of Transfer] >= N.[Date From] OR N.[Date From] is NULL) and ([Date of Transfer] <= N.[Date To] or N.[Date To] is NULL)
ORDER BY [ID], [Date of Transfer] ASC
我遇到的问题是位置表有时会延迟更新，因此客户转移不会加入任何有效位置。我想添加一个检查位置有效日期的子句。因此，在上面的例子中，我想将客户1的转账链接转移到8500转到转移后1个月左右更新的剑桥绿地址。有谁知道我怎么能做到这一点。
当前示例输出
ID Date of Transfer Old Location Location Address Date From Date To New Location Location Address Date From Date To
----------- ----------------------- ------------ -------------------------------------------------- ---------- ---------- ------------ -------------------------------------------------- ---------- ----------
1 2016-07-01 00:00:00.000 1001 Logan Street 1998-02-01 2017-07-21 2200 Ashdown Avenue 2014-01-31 NULL
1 2017-11-25 00:00:00.000 2200 Ashdown Avenue 2014-01-31 NULL 3078 Chessington Court 2009-05-11 2018-03-30
1 2018-01-01 00:00:00.000 3078 Chessington Court 2009-05-11 2018-03-30 8500 NULL NULL NULL
2 2016-02-27 00:00:00.000 5578 Aberdeen View 2000-11-19 2017-05-13 9901 Tay Road 2013-02-02 2018-01-22
2 2017-06-22 00:00:00.000 9901 Tay Road 2013-02-02 2018-01-22 9001 Wellington Way 2015-02-16 2018-02-22
客户1的最后一行尚未链接到某个位置，因为在转移期间没有列出该期间的位置。因此，我希望检查自转移日期以来该位置代码的下一个位置地址。
注意：位置表每个位置可以有多个地址（在不同的时间段内。因此，我不能使用简单的连接。
期望的输出。
ID Date of Transfer Old Location Location Address Date From Date To New Location Location Address Date From Date To
----------- ----------------------- ------------ -------------------------------------------------- ---------- ---------- ------------ -------------------------------------------------- ---------- ----------
1 2016-07-01 00:00:00.000 1001 Logan Street 1998-02-01 2017-07-21 2200 Ashdown Avenue 2014-01-31 NULL
1 2017-11-25 00:00:00.000 2200 Ashdown Avenue 2014-01-31 NULL 3078 Chessington Court 2009-05-11 2018-03-30
1 2018-01-01 00:00:00.000 3078 Chessington Court 2009-05-11 2018-03-30 8500 Cambridge Green 2018-01-15 2018-02-15
2 2016-02-27 00:00:00.000 5578 Aberdeen View 2000-11-19 2017-05-13 9901 Tay Road 2013-02-02 2018-01-22
2 2017-06-22 00:00:00.000 9901 Tay Road 2013-02-02 2018-01-22 9001 Wellington Way 2015-02-16 2018-02-22
答案 0 :(得分：1)
试试这个。
SELECT [ID]
,[Date of Transfer]
,[Old Location]
,O.[Location Address]
,O.[Date From]
,O.[Date To]
,[New Location]
,N.[Location Address]
,N.[Date From]
,N.[Date To]
FROM [dbo].[Customer]
Left Join [dbo].[Location] O on [Old Location] = O.[Location Code] and ([Date of Transfer] >= O.[Date From] OR O.[Date From] is NULL) and ([Date of Transfer] <= O.[Date To] or O.[Date To] is NULL)
Left Join [dbo].[Location] N on [New Location] = N.[Location Code] and ([Date of Transfer] >= N.[Date From] OR N.[Date From] is NULL or N.[Date To] is NULL) and ([Date of Transfer] <= N.[Date To] or N.[Date To] is NULL)
ORDER BY [ID], [Date of Transfer] ASC
答案 1 :(得分：0)
试试这个。
SELECT [ID]
,[Date of Transfer]
,[Old Location]
,O.[Location Address]
,O.[Date From]
,O.[Date To]
,[New Location]
,N.[Location Address]
,N.[Date From]
,N.[Date To]
FROM [dbo].[Customer]
Left Join [dbo].[Location] O on [Old Location] = O.[Location Code] and ([Date of Transfer] >= O.[Date From] OR O.[Date From] is NULL) and ([Date of Transfer] <= O.[Date To] or O.[Date To] is NULL)
Join [dbo].[Location] N on [New Location] = N.[Location Code] and ([Date of Transfer] >= N.[Date From] OR N.[Date From] is NULL) and ([Date of Transfer] <= N.[Date To] or N.[Date To] is NULL)
ORDER BY [ID], [Date of Transfer] ASC