msql 如何用"最小缺失数"实现日期的自动补全

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--如何用"最小缺失数"实现日期的自动补全

-->生成测试数据:

GO

IF OBJECT_ID('TBL')IS NOT NULL

DROP TABLE TBL

GO

CREATE TABLE TBL(

日期 DATE,

备注 VARCHAR(100)

)

GO

INSERT TBL

SELECT '2012-03-02','B' UNION ALL

SELECT '2012-03-05','C' UNION ALL

SELECT '2012-03-06','D' UNION ALL

SELECT '2012-03-07','E' UNION ALL

SELECT '2012-03-09','F' UNION ALL

SELECT '2012-03-11','G' UNION ALL

SELECT '2012-03-12','H' UNION ALL

SELECT '2012-03-13','I' UNION ALL

SELECT '2012-03-15','J' UNION ALL

SELECT '2012-03-19','K' UNION ALL

SELECT '2012-03-20','L'

GO

IF OBJECT_ID('P_SP')IS NOT NULL

DROP PROC P_SP

GO

CREATE PROC P_SP @ENDTIME DATE

AS

DECLARE @SQL VARCHAR(100)

SET @SQL='SELECT * FROM TBL ORDER BY 日期'

DECLARE @MINMISS DATE

SET @MINMISS=(

SELECT COALESCE(DATEADD(DD,1,MIN(A.日期)),

'2012-03-01') AS MISSING

FROM TBL A

WHERE NOT EXISTS(

SELECT * FROM TBL B

WHERE B.日期=DATEADD(DD,1,A.日期))

AND EXISTS (

SELECT 1 FROM TBL WHERE 日期='2012-03-01'))

PRINT @MINMISS

WHILE @MINMISS<=@ENDTIME

BEGIN

INSERT TBL(日期) VALUES(@MINMISS)

SELECT @MINMISS=(

SELECT DATEADD(DD,1,MIN(A.日期))

FROM TBL A

WHERE NOT EXISTS(

SELECT * FROM TBL B

WHERE B.日期=DATEADD(DD,1,A.日期))

)

END

EXEC(@SQL)

EXEC P_SP '2012-03-20'

/*

日期 备注

2012-03-01 NULL

2012-03-02 B

2012-03-03 NULL

2012-03-04 NULL

2012-03-05 C

2012-03-06 D

2012-03-07 E

2012-03-08 NULL

2012-03-09 F

2012-03-10 NULL

2012-03-11 G

2012-03-12 H

2012-03-13 I

2012-03-14 NULL

2012-03-15 J

2012-03-16 NULL

2012-03-17 NULL

2012-03-18 NULL

2012-03-19 K

2012-03-20 L

*/

--------------------------------------------------

--------------------------------------------------

-->生成测试数据:

GO

IF OBJECT_ID('TBL')IS NOT NULL

DROP TABLE TBL

GO

CREATE TABLE TBL(

日期 DATE

)

GO

INSERT TBL

SELECT '2012-03-01' UNION ALL

SELECT '2012-03-31'

--利用递归实现输出三月份的所有日期：

go

declare @date date

select @date=MAX(日期) from tbl

;with t

as(

select * from tbl

union all

select dateadd(dd,1,a.日期) from t a

where not exists(select * from tbl b

where b.日期=DATEADD(DD,1,a.日期)

)

and a.日期<@date

)

select *from t order by 日期

/*

日期

2012-03-01

2012-03-02

2012-03-03

2012-03-04

2012-03-05

2012-03-06

2012-03-07

2012-03-08

2012-03-09

2012-03-10

2012-03-11

2012-03-12

2012-03-13

2012-03-14

2012-03-15

2012-03-16

2012-03-17

2012-03-18

2012-03-19

2012-03-20

2012-03-21

2012-03-22

2012-03-23

2012-03-24

2012-03-25

2012-03-26

2012-03-27

2012-03-28

2012-03-29

2012-03-30

2012-03-31

*/来自: http://www.52mvc.com/showtopic-562.aspx