根据有效日期选择相关记录的sql语句怎么写,请指导!
根据有效日期选择相关记录的sql语句如何写,请指导!......
table1: id,name,effdate
(1,aaa,2012-01-01)
(1,aaa,2012-03-10)
(1,aaa,2012-05-01)
(2,bbb,2012-02-01)
(2,bbb,2012-04-01)
......
table2: id,searchdate,...
(1,2012-02-02)
(1,2012-03-20)
...
(2,2012-03-02)
...
想要的结果是对应table2日期最近有效的table1记录。
如:
(1,2012-02-02,aaa,2012-01-01)
(1,2012-03-20,aaa,2012-03-10)
(2,2012-03-02,bbb,2012-02-01)
...
------解决方案--------------------
table1: id,name,effdate
(1,aaa,2012-01-01)
(1,aaa,2012-03-10)
(1,aaa,2012-05-01)
(2,bbb,2012-02-01)
(2,bbb,2012-04-01)
......
table2: id,searchdate,...
(1,2012-02-02)
(1,2012-03-20)
...
(2,2012-03-02)
...
想要的结果是对应table2日期最近有效的table1记录。
如:
(1,2012-02-02,aaa,2012-01-01)
(1,2012-03-20,aaa,2012-03-10)
(2,2012-03-02,bbb,2012-02-01)
...
------解决方案--------------------
- SQL code
CREATE TABLE TABLE1 ( Id INT, Name VARCHAR(100), Effdate DATETIME ) GO INSERT INTO TABLE1 SELECT 1,'aaa','2012-01-01' UNION SELECT 1,'aaa','2012-03-10' UNION SELECT 1,'aaa','2012-05-01' UNION SELECT 2,'bbb','2012-02-01' UNION SELECT 2,'bbb','2012-04-01' CREATE TABLE table2 ( id INT, searchdate DATETIME) GO INSERT INTO Table2 SELECT 1,'2012-02-02' UNION SELECT 1,'2012-03-20' UNION SELECT 2,'2012-03-02' WITH TableA AS (SELECT B.Id,searchdate,name,Effdate,DATEDIFF(DAY,Effdate,searchdate) AS Diff FROM TABLE1 AS A,Table2 AS B WHERE A.id = B.Id AND DATEDIFF(DAY,Effdate,searchdate) > 0) SELECT Id,searchdate,name,Effdate FROM TableA AS A WHERE Diff <= ALL(SELECT Diff FROM TableA AS B WHERE A.Id = B.Id AND A.Effdate = B.Effdate) Id searchdate name Effdate 1 2012-02-02 00:00:00.000 aaa 2012-01-01 00:00:00.000 1 2012-03-20 00:00:00.000 aaa 2012-03-10 00:00:00.000 2 2012-03-02 00:00:00.000 bbb 2012-02-01 00:00:00.000
------解决方案--------------------
- SQL code
select a.id,b.searchdate,a.name,a.effdate from table1 a left outer join table2 b on a.id=b.id where not exists (select 1 from table1 ,table2 where abs(datediff(dd,effdate,b.searchdate))<abs(datediff(dd,a.effdate,b.searchdate)))