更新
我添加了一个数据集示例，因此更容易解释我的问题。在我看来它是否是一个查询问题。
我有2013-01至2014-12所有月份的基准。我有一个查询表，每人的合同工作时间（列ID;例如，人1和人2）。
我必须将该基准月份与该月份的正确合约时数相匹配。查找表提供有关工作周时间变化的历史信息。
有人可以帮助我进行此加入或查找吗？
示例结果人1 ：2013年4月（2013-04）的合约时数应为16小时。因为在查询表中他从2013-02-18开始工作了16个小时，并在2013-04-16开始工作了8个小时。
示例结果人2 ：他的最后一次合同变更是2012-11-01至32小时。所以2013年的所有月份和2014年必须是32小时。
CREATE TABLE [dbo].[_Lookup](
[ID] [int] NOT NULL,
[Date] [nvarchar](50) NULL,
[Hours] [int] NULL
) ON [PRIMARY]
GO
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2013-01-01 00:00:00', 8)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2013-02-18 00:00:00', 16)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2013-04-16 00:00:00', 8)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2013-05-01 00:00:00', 32)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2013-09-15 00:00:00', 12)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2013-10-01 00:00:00', 20)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (1, N'2015-01-01 00:00:00', 12)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2008-01-01 00:00:00', 24)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2009-03-01 00:00:00', 36)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2009-08-31 00:00:00', 24)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2010-02-01 00:00:00', 36)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2010-04-01 00:00:00', 30)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2011-08-01 00:00:00', 24)
INSERT [dbo].[_Lookup] ([ID], [Date], [Hours]) VALUES (2, N'2012-11-01 00:00:00', 32)
CREATE TABLE [dbo].[_Basetable](
[ID] [int] NOT NULL,
[Date] [datetime] NULL
) ON [PRIMARY]
GO
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A13900000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A15800000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A17400000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A19300000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A1B100000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A1D000000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A1EE00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A20D00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A22C00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A24A00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A26900000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A28700000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A2A600000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A2C500000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A2E100000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A30000000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A31E00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A33D00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A35B00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A37A00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A39900000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A3B700000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A3D600000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (1, CAST(0x0000A3F400000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A13900000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A15800000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A17400000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A19300000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A1B100000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A1D000000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A1EE00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A20D00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A22C00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A24A00000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A26900000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A28700000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A2A600000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A2C500000000 AS DateTime))
INSERT [dbo].[_Basetable] ([ID], [Date]) VALUES (2, CAST(0x0000A2E100000000 AS DateTime))
-- The result table should look like this:
--
--
-- ID Date
-- 1 2013-01-01 8
-- 1 2013-02-01 8
-- 1 2013-03-01 16
-- 1 2013-04-01 16
-- 1 2013-05-01 32
-- 1 2013-06-01 32
-- 1 2013-07-01 32
-- 1 2013-08-01 32
-- 1 2013-09-01 32
-- 1 2013-10-01 20
-- 1 2013-11-01 20
-- 1 2013-12-01 20
-- 1 2014-01-01 20
-- 1 2014-02-01 20
-- 1 2014-03-01 20
-- 1 2014-04-01 20
-- 1 2014-05-01 20
-- 1 2014-06-01 20
-- 1 2014-07-01 20
-- 1 2014-08-01 20
-- 1 2014-09-01 20
-- 1 2014-10-01 20
-- 1 2014-11-01 20
-- 1 2014-12-01 20
-- 2 2013-01-01 32
-- 2 2013-02-01 32
-- 2 2013-03-01 32
-- 2 2013-04-01 32
-- 2 2013-05-01 32
-- 2 2013-06-01 32
-- 2 2013-07-01 32
-- 2 2013-08-01 32
-- 2 2013-09-01 32
-- 2 2013-10-01 32
-- 2 2013-11-01 32
-- 2 2013-12-01 32
-- 2 2014-01-01 32
-- 2 2014-02-01 32
-- 2 2014-03-01 32
答案 0 :(得分：1)
这对你有用吗？
WITH MyTimeDate ([Year], [Month], Hours_Work) AS
(
SELECT 2013, 1, 8 UNION ALL
SELECT 2013, 2, 16 UNION ALL
SELECT 2013, 4, 8 UNION ALL
SELECT 2013, 5, 32 UNION ALL
SELECT 2013, 9, 12 UNION ALL
SELECT 2013, 10, 20 UNION ALL
SELECT 2015, 1, 12
)
,MySampleCal ([Year], [Month]) AS
(
SELECT 2013, 1 UNION ALL
SELECT 2013, 2 UNION ALL
SELECT 2013, 3 UNION ALL
SELECT 2013, 4 UNION ALL
SELECT 2013, 5 UNION ALL
SELECT 2013, 6 UNION ALL
SELECT 2013, 7 UNION ALL
SELECT 2013, 8 UNION ALL
SELECT 2013, 9 UNION ALL
SELECT 2013, 10 UNION ALL
SELECT 2013, 11 UNION ALL
SELECT 2013, 12
)
,DistanceCTE AS
(
SELECT C.[Year]
,C.[Month]
,D.Hours_Work
,DistanceSeq = ROW_NUMBER() OVER (PARTITION BY C.[Year], C.[Month] ORDER BY D.[Month] - C.[Month] DESC)
FROM MySampleCal C
JOIN MyTimeDate D ON C.[Year] = D.[Year]
AND C.[Month] >= D.Month
)
SELECT *
FROM DistanceCTE
WHERE DistanceSeq = 1
答案 1 :(得分：0)
从您对问题的简短描述中我可以提供以下帮助
如果您在两个表上都有相同的ID，那么
SELECT b.Jaar, b.Maand, a.Jaar, a.Maand ,a.Hours_Work,ISNULL(SUM(b.Hours_Work),0) FROM b
LEFT JOIN a ON a.Key = b.Key
或根据Year和month
SELECT b.Jaar, b.Maand, a.Jaar, a.Maand FROM s LEFT JOIN
a ON a.Hours_Work = b.Hours_Work and a.Jaar = b.Jaar and a.Maand = b.Month
希望它有所帮助。
如果没有，请说明。
答案 2 :(得分：0)
这就是答案：
Select A.ID
, A.Date
, ( Select Top 1
B.Hours
From _Lookup B
Where A.Date >= B.Date
and A.Id = B.ID
Order by B.Date desc
) as WorkingHours
From [_Basetable] A
感谢您帮助我!!