mtwm.net
当前位置:首页 >> mysql sum DistinCt >>

mysql sum DistinCt

select sum(distinct priceavg) from statistics where month in(3,4,5) 查看原帖>>

select (select u._netName from t_gw_netuser u where u._netName = a._uid) _netName, (select w._urlName from t_gw_websiteurl w where w._urlId = w._url) _urlName, count(distinct a._url) CUrl, count(a._host) CHost, sum(a._count) SC...

select 学号, avg(分数) from grade group by 学号 having count(distinct 课程编号) > 1select 学号 as u_编号, 姓名 as u_名称...

WITH a1 AS(SELECT id ,max(price) AS price FROM a GROUP BY id)SELECT sum(price) FROM a1

select sum(cnt) from ( select count(*) as cnt from tb_one where title like '%蜡笔小新%' union all select count(*) as cnt from tb_two where title like '%蜡笔小新%' union all select count(*) as cnt from tb_three where title like ...

eASY! SELECT DISTINCT DATE_FORMAT(date,'%Y-%d') FROM XXX

可以,distinct是sql的语法,不是dbms里特有的 用法相同

一个表有可能在同一列中有重复的值。例如,数据库pubs的表authors中有两个作者的名字是Ringer。如果你从这个表中取出所有的名字,名字Ringer将会显示两次。 在特定情况下,你可能只有兴趣从一个表中取出互不相同的值。如果一个字段有重复的值,...

那里在之前先用where 过滤掉空值不就可以了吗? 不知道你的具体环境是怎样的,可以这样试试:where 字段 is NOT NULL and 字段''

加上group by channel_name

网站首页 | 网站地图
All rights reserved Powered by www.mtwm.net
copyright ©right 2010-2021。
内容来自网络,如有侵犯请联系客服。zhit325@qq.com