嗨,我是 SQL Server 2008 的新手
我想根据另一个列将单行扩展到多行,
例如
date value
7-2011 5
结果:
2011-07-01
2011-08-01
2011-09-01
2011-10-01
2012-11-01
日期应该是当前和下个月的第一天,重复 5 次
嗨,我是 SQL Server 2008 的新手
我想根据另一个列将单行扩展到多行,
例如
date value
7-2011 5
结果:
2011-07-01
2011-08-01
2011-09-01
2011-10-01
2012-11-01
日期应该是当前和下个月的第一天,重复 5 次
尝试:
DECLARE @YourTable table (YourDate datetime, value int)
insert into @YourTable VALUES ('2011-7-12',5)
;WITH AllNumbers AS
(
SELECT 0 AS Number
UNION ALL
SELECT Number+1
FROM AllNumbers
WHERE Number<4
)
SELECT
dateadd(month,number,DATEADD(month,DATEDIFF(month,0,YourDate),0))
FROM @YourTable y
INNER JOIN AllNumbers a ON 1=1
输出:
-----------------------
2011-07-01 00:00:00.000
2011-08-01 00:00:00.000
2011-09-01 00:00:00.000
2011-10-01 00:00:00.000
2011-11-01 00:00:00.000
(5 row(s) affected)
它适用于表中的多行,请参见此处:
DECLARE @YourTable table (YourDate datetime, ValueOf int)
insert into @YourTable VALUES ('2011-7-12',5)
insert into @YourTable VALUES ('2012-4-24',6)
;WITH AllNumbers AS
(
SELECT 0 AS Number
UNION ALL
SELECT Number+1
FROM AllNumbers
WHERE Number<4
)
SELECT
y.ValueOf
,dateadd(month,number,DATEADD(month,DATEDIFF(month,0,y.YourDate),0))
FROM @YourTable y
INNER JOIN AllNumbers a ON 1=1
ORDER BY 1,2
输出:
ValueOf
----------- -----------------------
5 2011-07-01 00:00:00.000
5 2011-08-01 00:00:00.000
5 2011-09-01 00:00:00.000
5 2011-10-01 00:00:00.000
5 2011-11-01 00:00:00.000
6 2012-04-01 00:00:00.000
6 2012-05-01 00:00:00.000
6 2012-06-01 00:00:00.000
6 2012-07-01 00:00:00.000
6 2012-08-01 00:00:00.000
(10 row(s) affected)
另外,我没有可用的 SQL Server 2008,所以我使用了 datetime,如果你有 2008,你可以使用DATE
datatype 并且你不必设置 datetime,所以使用这一行:
dateadd(month,number,y.YourDate)
create function addMonths(@date date, @limit int)
returns @date_table TABLE(
myDate date
)
AS
begin
declare @cont int
set @cont = 1
while (@cont <= @limit) begin
insert into @date_table values(DATEADD(MONTH,@cont,@date))
set @cont=@cont+1
end
return
end
用法:
select * from addMonths(GETDATE(),5)
编辑:
create table mydates(
myDate date,
inc_months int)
insert into mydates values ('01/01/2005',3)
insert into mydates values ('01/01/2006',5)
select AM.mydate
from mydates MD cross apply addMonths(MD.mydate,MD.inc_months) AM
结果:
2005-02-01
2005-03-01
2005-04-01
2006-02-01
2006-03-01
2006-04-01
2006-05-01
2006-06-01