最近遇到一個行轉列的問題，給定一個時間段，統計每天每個車的簽到情況，用動態拼接的方法實現，受Varchar(8000)的影響，拼接的SQL語句不能太長，遇到這種動態列頭的問題，這種方法肯定不是很好，希望有高人指點新招~

/*建立車信息表*/

go if NOT EXISTS (select 1 from sysobjects where id = object_id('Car') AND type='U') BEGIN CREATE TABLE Car (Carid UNIQUEIDENTIFIER ,CarName VARCHAR(100)) end go /*插入一些數據*/ INSERT INTO Car SELECT NEWID(),'car1' UNIONSELECT NEWID(),'car2' UNIONSELECT NEWID(),'car3' UNIONSELECT NEWID(),'car4' UNIONSELECT NEWID(),'car5' UNIONSELECT NEWID(),'car6' UNIONSELECT NEWID(),'car7' /*建立簽到表*/ go if NOT EXISTS (select 1 from sysobjects where id = object_id('CarTime') AND type='U') BEGIN CREATE TABLE CarTime (CarTimeID UNIQUEIDENTIFIER ,CarId UNIQUEIDENTIFIER, operateDate DATETIME) END go /*插入一些數據*/ DECLARE @i INT SET @i=1 WHILE (@i<=10) BEGIN INSERT INTO CarTime SELECT NEWID(),CarId,'2012-08-'+CONVERT(VARCHAR(10),@i) FROM CarSET @i=@i+1 end /*統計一段時間所有車每天的簽到情況*/ go if EXISTS (select 1 from sysobjects where id = object_id('sp_CarTimeReport') AND type='P') BEGIN DROP PROC sp_CarTimeReport END go CREATE PROC [dbo].[sp_CarTimeReport] @BeginDate DATETIME, @EndDate DATETIME AS BEGIN DECLARE @begin DATETIME DECLARE @end DATETIME SET @begin=CONVERT(DATETIME,CONVERT(VARCHAR(10),@BeginDate,120)) SET @end=CONVERT(DATETIME,CONVERT(VARCHAR(10),@EndDate,120)) DECLARE @index DATETIME SET @index=@begin DECLARE @sql VARCHAR(8000) SET @sql=' SELECT car.CarName as 車名' WHILE(@index<=@end) BEGIN SET @sql=@sql+' ,case when sum(case when convert(varchar(10),carTime.OperateDate,120)='''+ CONVERT(VARCHAR(10),@index,120) +''' then 1 else null end) is not null then ''√'' else null end as '''+ CONVERT(VARCHAR(10),@index,120) +''' ' SET @index=@index+1 end SET @sql=@sql+' FROM Car left join CarTime on Car.carid=CarTime.carid group by Car.carid,car.CarName order by Car.CarName ' EXEC(@sql) END --DROP TABLE car --DROP TABLE cartime --DROP PROC sp_CarTimeReport--EXEC sp_CarTimeReport '2012-08-01','2012-08-30'

運行效果如下：

總結

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