动态SQL

　　我觉得非常有必要写篇文章来讲一下动态SQL，待补充...

　　

declare @column varchar(10)
declare @time varchar(10)
declare @time2 varchar(10)
declare @sql varchar(4000)
set @column=(select 'd'+CONVERT(varchar,DAY(GETDATE()-1))) 
set @time=(select left(convert(varchar,getdate(),21),7))
set @time2=(select left(convert(varchar,getdate()-1,21),10))
set @sql='update a set
a.'+@column+'=b.InWater
from WEB_MonthData a , [IPLHSC].[JY].dbo.BAProduceData  b
where  a.Date_Month='''+@time+''' and b.time_stamp='''+@time2+'''
and a.ID in(105030) and b.Item=''龙华水司''

update a set
a.'+@column+'=b.OutWater
from WEB_MonthData a , [IPLHSC].[JY].dbo.BAProduceData  b
where  a.Date_Month='''+@time+''' and b.time_stamp='''+@time2+'''
and a.ID in(105027) and b.Item=''龙华水司'''

print @sql
exec (@sql)