ID TagValue DATESTR
1 23 2017-01-25 12:01:48.007
2 34 2017-01-25 12:01:48.007
3 44 2017-01-25 12:01:48.007
1 25 2017-02-25 12:01:48.007
2 36 2017-02-25 12:01:48.007
3 46 2017-02-25 12:01:48.007
1 27 2017-03-25 12:01:48.007
2 36 2017-03-25 12:01:48.007
3 48 2017-03-25 12:01:48.007
1 29 2017-04-25 12:01:48.007
2 38 2017-04-25 12:01:48.007
3 50 2017-04-25 12:01:48.007
1 31 2017-05-25 12:01:48.007
2 40 2017-05-25 12:01:48.007
3 52 2017-05-25 12:01:48.007
1 33 2017-06-25 12:01:48.007
2 42 2017-06-25 12:01:48.007
3 54 2017-06-25 12:01:48.007
1 44 2017-07-25 12:01:48.007
2 46 2017-07-25 12:01:48.007
3 56 2017-07-25 12:01:48.007
1 48 2017-08-25 12:01:48.007
2 58 2017-08-25 12:01:48.007
这是我的主表，其中值与日期时间一致
ID LastMonthvalue CurrentMonthValue DATESTR
1 23 25 2017-03-28 12:01:48.007
2 34 36 2017-03-28 12:01:48.007
3 44 46 2017-03-28 12:01:48.007
这是我的第二个表，我想根据我的主表更新LastMonth Value和CurrentMonth Value，因为你可以看到我的主表中添加了新值（ID = 1）在我的第二个表中我已经有3个ID了值假设我想今天更新我的第二张表2017-08-30，而不是更新2017-07-25的lastMonthValue值和2017-08-25从Master表更新CurrentMonth值
答案 0 :(得分：0)
一个月内可能有多行吗？
;with tb(ID,TagValue,TagValue1,DATE) AS (
select 1,234,345,'2017-07-21 13:15:09.387' union all
select 2,444,555,'2017-07-21 13:15:09.387' union all
select 1,356,545,'2017-08-21 13:15:09.387'
)
select ID
,sum(case when datediff(month,[DATE],getdate())=1 then TagValue else 0 end) as LastMonth
,sum(case when datediff(month,[DATE],getdate())=0 then TagValue else 0 end) as CurrentMonth
from tb
where datediff(month,[DATE],getdate())<=1
group by ID
ID LastMonth CurrentMonth 1 1 234 356 2 2 444 0
答案 1 :(得分：0)
我创建了两个答案，一个用于SQL Server 2008，另一个用于2012年以上。
这种逻辑如何运作
也许，您需要做一些调整才能实现目标
DECLARE @Master AS TABLE
(
id INT,
TagValue INT,
DATESTR DATETIME
)
DECLARE @Second as table (
ID int , LastMonthValue int, CurrentMonthValue int, DATESTR date)
INSERT @Second
VALUES
(1 ,23 ,25 ,'2017-03-28 12:01:48.007')
,(2 ,34 ,36 ,'2017-03-28 12:01:48.007')
,(3 ,44 ,46 ,'2017-03-28 12:01:48.007')
INSERT @Master
VALUES
(1 ,23 ,'2017-01-25 12:01:48.007')
,(2 ,34 ,'2017-01-25 12:01:48.007')
,(3 ,44 ,'2017-01-25 12:01:48.007')
,(1 ,25 ,'2017-02-25 12:01:48.007')
,(2 ,36 ,'2017-02-25 12:01:48.007')
,(3 ,46 ,'2017-02-25 12:01:48.007')
,(1 ,27 ,'2017-03-25 12:01:48.007')
,(2 ,36 ,'2017-03-25 12:01:48.007')
,(3 ,48 ,'2017-03-25 12:01:48.007')
,(1 ,29 ,'2017-04-25 12:01:48.007')
,(2 ,38 ,'2017-04-25 12:01:48.007')
,(3 ,50 ,'2017-04-25 12:01:48.007')
,(1 ,31 ,'2017-05-25 12:01:48.007')
,(2 ,40 ,'2017-05-25 12:01:48.007')
,(3 ,52 ,'2017-05-25 12:01:48.007')
,(1 ,33 ,'2017-06-25 12:01:48.007')
,(2 ,42 ,'2017-06-25 12:01:48.007')
,(3 ,54 ,'2017-06-25 12:01:48.007')
,(1 ,44 ,'2017-07-25 12:01:48.007')
,(2 ,46 ,'2017-07-25 12:01:48.007')
,(3 ,56 ,'2017-07-25 12:01:48.007')
,(1 ,48 ,'2017-08-25 12:01:48.007')
,(2 ,58 ,'2017-08-25 12:01:48.007')
更新前
SELECT * FROM @Second
ID LastMonthValue CurrentMonthValue DATESTR
----------- -------------- ----------------- ----------
1 23 25 2017-03-28
2 34 36 2017-03-28
3 44 46 2017-03-28
Code ror SQL Server 2008
;WITH
cte_PreviousMonth
as
(
Select Distinct
Id
,DateAdd(M,-1,Cast(CAST(Datepart(YYYY, Max(DATESTR) Over (Partition by Id)) * 100 + Datepart(MM, Max(DATESTR) Over (Partition by Id)) as char(6)) +'01' as date)) DATESTR_Previous
,Cast(CAST(Datepart(YYYY, Max(DATESTR) Over (Partition by Id)) * 100 + Datepart(MM, Max(DATESTR) Over (Partition by Id)) as char(6)) +'01' as date) DATESTR_CurrentStartMonth
,DATESTR
from @Master
)
,cte_Dates as
(
Select Distinct A.Id ,
Max(A.DATESTR) Over (Partition by A.Id) DATESTR_Previous
,Max(B.DATESTR) Over (Partition by B.Id) DATESTR_Current
from @Master A
INNER JOIN cte_previousMonth b
On
a.id = b.id and a.DATESTR >= b.DATESTR_Previous and a.DATESTR < b.DATESTR_CurrentStartMonth
)
,cte_Main AS
(
SELECT Row_number()
OVER (
partition BY id
ORDER BY DATESTR) rn
,*
FROM @Master A
where exists (Select 1 from cte_Dates b where a.id =b.id and (a.DATESTR = b.DATESTR_Previous or a.DATESTR = b.DATESTR_Current))
)
,cte_MainCurrent as (
SELECT ROW_NUMBER() over (partition by a.id order by a.DATESTR desc) rn
,a.id
,a.DATESTR
,b.tagvalue LastMonthvalue
,a.tagvalue CurrentMonthValue
FROM cte_Main a
LEFT JOIN cte_Main b
ON a.id = b.id
AND a.rn = b.rn + 1
)
UPDATE
S
SET
LastMonthValue = M.LastMonthvalue
,CurrentMonthValue = M.CurrentMonthValue
,DATESTR = M.DATESTR
FROM @Second S
INNER JOIN cte_MainCurrent M
On
S.ID = M.id
WHERE
M.rn = 1
上面的SQL Server 2012代码
;WITH
cte_PreviousMonth
as
(
Select Distinct
Id
,DateAdd(M,-1,Cast(CAST(Datepart(YYYY, Max(DATESTR) Over (Partition by Id)) * 100 + Datepart(MM, Max(DATESTR) Over (Partition by Id)) as char(6)) +'01' as date)) DATESTR_Previous
,Cast(CAST(Datepart(YYYY, Max(DATESTR) Over (Partition by Id)) * 100 + Datepart(MM, Max(DATESTR) Over (Partition by Id)) as char(6)) +'01' as date) DATESTR_CurrentStartMonth
,DATESTR
from @Master
)
,cte_Dates as
(
Select Distinct A.Id ,
Max(A.DATESTR) Over (Partition by A.Id) DATESTR_Previous
,Max(B.DATESTR) Over (Partition by B.Id) DATESTR_Current
from @Master A
INNER JOIN cte_previousMonth b
On
a.id = b.id and a.DATESTR >= b.DATESTR_Previous and a.DATESTR < b.DATESTR_CurrentStartMonth
)
,cte_MainCurrent as (
SELECT ROW_NUMBER() over (partition by a.id order by a.DATESTR desc) rn
,id
,DATESTR
,Lag(tagvalue, 1, NULL)
OVER (
partition BY id
ORDER BY DATESTR) LastMonthvalue,
tagvalue CurrentMonthValue
FROM @Master a
where exists (Select 1 from cte_Dates b where a.id =b.id and (a.DATESTR = b.DATESTR_Previous or a.DATESTR = b.DATESTR_Current))
)
UPDATE
S
SET
LastMonthValue = M.LastMonthvalue
,CurrentMonthValue = M.CurrentMonthValue
,DATESTR = M.DATESTR
FROM @Second S
INNER JOIN cte_MainCurrent M
On
S.ID = M.id
WHERE
M.rn = 1
更新后
SELECT * FROM @Second
ID LastMonthValue CurrentMonthValue DATESTR
----------- -------------- ----------------- ----------
1 44 48 2017-08-25
2 46 58 2017-08-25
3 54 56 2017-07-25