問(wèn)題描述

-- phpMyAdmin SQL Dump-- version 4.0.10.14-- http://www.phpmyadmin.net---- 主機(jī): localhost:3306-- 生成日期: 2016-08-24 00:16:24-- 服務(wù)器版本: 5.6.30-cll-lve-- PHP 版本: 5.6.20SET SQL_MODE = 'NO_AUTO_VALUE_ON_ZERO';SET time_zone = '+00:00';/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;/*!40101 SET NAMES utf8 */;---- 數(shù)據(jù)庫(kù): `student`---- ------------------------------------------------------------ 表的結(jié)構(gòu) `student`--CREATE TABLE IF NOT EXISTS `student` ( `id` varchar(20) NOT NULL, `name` varchar(50) NOT NULL, `fraction` int(20) NOT NULL, `date` date NOT NULL) ENGINE=MyISAM DEFAULT CHARSET=latin1;---- 轉(zhuǎn)存表中的數(shù)據(jù) `student`--INSERT INTO `student` (`id`, `name`, `fraction`, `date`) VALUES(’1’, ’student’, 100, ’2016-08-23’),(’1’, ’student’, 95, ’2016-08-22’),(’2’, ’student2’, 100, ’2016-08-23’),(’2’, ’student2’, 200, ’2016-08-22’),(’3’, ’student3’, 350, ’2016-08-23’),(’3’, ’student3’, 450, ’2016-08-22’),(’4’, ’student4’, 50, ’2016-08-23’),(’4’, ’student4’, 100, ’2016-08-22’),(’5’, ’student5’, 900, ’2016-08-23’),(’5’, ’student5’, 930, ’2016-08-22’);/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

MYSQL中的數(shù)據(jù)

需求:按照下面最終目的對(duì)比 昨天和前天的數(shù)據(jù)（因?yàn)槊刻於家獙?duì)比最近兩天的數(shù)據(jù)）

需要sql查詢語(yǔ)句來(lái)實(shí)現(xiàn)以下效果

問(wèn)題解答

select t1.name as 姓名, t1.fraction as 昨天分?jǐn)?shù), t2.fraction as 前天分?jǐn)?shù), current_date as 今天日期from ( select id,name,fraction from student where date = (current_date - interval 1 day) -- 昨天) t1left outer join ( select id,fraction from student where date = (current_date - interval 2 day) -- 前天) t2 on t1.id = t2.id

select t_22.name, t_22.fraction, t_23.fractionfrom (select name, fraction from student where data=’2016-08-22’) t_22, (select name, fraction from student where data=’2016-08-23’) t_23where t_22.name=t_23.name

有空再看看能不能優(yōu)化吐槽:題主的id等于沒(méi)用,id一般用來(lái)做主鍵必然是唯一性的...