count(distinct 订单号)和count(*)as 订单数`````group by 订单号,这两个语句是不是
count(distinct 订单号)和count(*)as 订单数`````group by 订单号,这两个语句是不是
group by zuozhebianhao having count(*)>=3
group by 和 distinct 的问题
SQL语句中的 Distinct 和 Group by 有什么不同,用那个好?
group by 零件号 having count(项目号)=3
group by o.ownerid having count(o.id)>=2
oracle中 HAVING count(1) group by sex having count(*)>4; 怎么使用
select telnum,count(0),count(distinct othertelnum) from nmk.
count,count和count的区别
count
select count(*) as total from 'test' order by id desc
这样的SQL select语句怎么写?怎么显示数据 distinct,order by,group by,having?