一条例子： selectcount(point_id)astoday_sumfrompointwheredatediff(d,point_date,getdate())=0 关键语句： datediff(d,point_date,getdate())=0
一条例子： select count(point_id) as today_sum from point where datediff(d,point_date,getdate())=0 关键语句： datediff(d,point_date,getdate())=0
