SQL 获取上午下午
--方法一：select sum(casewhen (datepart(hour,pretime)>0 and datepart(hour,pretime)<12) then 1else 0 end) as 上午,sum(casewhen (datepart(hour,pretime)>12 and datepart(hour,pretime)<23) then 1else 0 end)as 下午from preorderwherepretime>'2011-2-1'and pretime<'2011-7-7'--方法二：select t = datepart(Hour,pretime) from preorder >12下午。=<12上午--上午：if not (select object_id('Tempdb..#temp')) is null drop table #tempselect datepart(Hour,pretime) as numinto #tempfrom preordergoselect count(*) from #tempwhere num>0 and num <13--下午：if not (select object_id('Tempdb..#temp')) is null drop table #tempselect datepart(Hour,pretime) as numinto #tempfrom preordergoselect count(*) from #tempwhere num>12?