清空数据库数据，表

declare @sql varchar(1000)
declare @cot int
declare @i int
set @i=1 
select @cot =COUNT(*)  from sysobjects WHERE (type = 'U')
select @cot
while @i<=@cot
begin 
select @sql = 'drop table ' + name  from sysobjects WHERE (type = 'U') ORDER BY 'drop table ' + name
select @sql
exec(@sql)
set @i=@i+1 
end 

drop table ?
delete ?
truncate table ?