650) This. width = 650; "src =" http://s3.51cto.com/wyfs02/M02/43/7C/wKioL1PbTSWDqRH1AAEHUY79-XQ615.jpg "style =" float: none; "Title =" 11136.jpg" alt = "wKioL1PbTSWDqRH1AAEHUY79-XQ615.jpg"/>
650) This. width = 650; "src =" http://s3.51cto.com/wyfs02/M01/43/7C/wKiom1PbTAzik9o1AAFa9t-PlLc179.jpg "style =" float: none; "Title =" 2228.jpg" alt = "wKiom1PbTAzik9o1AAFa9t-PlLc179.jpg"/>
650) This. width = 650; "src =" http://liaozhengchao.blog.51cto.com/e/u261/themes/default/images/spacer.gif "style =" Background: URL ("/e/u261/lang/ZH-CN/images/localimage.png") No-repeat center; border: 1px solid # DDD; "alt =" spacer.gif "/> Create Table ABC (
Baduser number (3 ),
Playuser number (3)
);
Select T. *, rowid from abc t;
Select sum (baduser)/sum (playuser), -- 1
Sum (baduser/playuser)/count (*), -- 2
AVG (baduser/playuser) -- 3
From ABC;
2 and 3 are the same results,
1 different
Currently, we need to determine the proportion of users with poor quality. Do we use 1 or 23?
The first is the percentage of total quality difference, and the second is the percentage of average quality difference.
This article is from the "JianHu Liao zhengchao" blog, please be sure to keep this source http://liaozhengchao.blog.51cto.com/7203056/1533839