方法一:
if exists (select * from tempdb.dbo.sysobjects where id = object_id(N'tempdb..#tempcitys') and type='U')
drop table #tempcitys
注意tempdb后面是两个. 不是一个的
方法二:
if object_id('tempdb..#tem') is not null
begin
print 'exists'
end
else
begin
print 'not exists'
end