前端工程师的mysql笔记

背景

最近常参与后台php项目，虽说刚毕业时自学过一阵子php和mysql，不过长时间没用也忘差不多了，于是把mysql再温习一遍，前端同学也可以一起学习下！

mysql安装以及操作

安装

brew install mysql

启动

$: mysql.server start

关闭

$:mysql.server stop

连接

$:mysql -u root -p

检查mysql进程

ps -ef | grep mysqld

问题

重启mysql提示MySQL server PID file could not be found!

1. ps -ef|grep mysqld 
2. kill -9 进程号 

DML&DDL

数据操作语言DML

• select
• update
• delete
• insert into

数据定义语言DDL

• crate database
• alter database
• create table
• alter table
• drop table
• crate index
• drop index

SQL

基础操作

创建数据库

mysql> create database test

查看数据库

mysql>  show databases;

使用test数据库

mysql>  use test

查看表

mysql>  show tables;

一，基础教程

创建表

mysql> create table person (id int(4) not null primary key auto_increment,lastname varchar(20) not null,firstname varchar(20),age int(4),sex int(4) not null,address varchar(20));

插入数据

mysql> insert into person  value (null,'hao','jery',13,1,'beijing');

删除一行数据

mysql> delete from person where id  = 4;

查询去重

mysql> select distinct lastname from person;

where

mysql> select * from person where address = 'beijing';

and

mysql> select * from person where age>13 and age<26;

or

mysql> select * from person where age<20 or age >25;

order by

mysql> select * from person order by age;
mysql> select lastname,age from person order by age;
mysql> select lastname,age from person order by age asc; //顺序显示
mysql> select lastname,age from person order by age desc;//逆向显示

update

 mysql> update person set lastname='zhuxiaoxiao' where lastname='du';
 mysql> update person set lastname='update',age=27 where id = 12;

delete

mysql> delete from person where lastname ='zhixiang';

一览