MySQL基础01-简介

一、MySQL启动方式

1、Windows：

方法一：
以管理员身份运行cmd打开dos窗口，输入net start mysql80。(mysql80为实际服务名称)

C:\Users\Administrator>net start mysql80
MySQL80 服务正在启动 .
MySQL80 服务已经启动成功。
C:\Users\Administrator>net stop mysql80
MySQL80 服务正在停止.
MySQL80 服务已成功停止。

方法二：用cmd输入services.msc打开windows服务，找到MySQL服务右键点击启动。

2、Linux：

service mysql start  # 启动
service mysql stop  # 停止
service mysql restart  # 重启
service mysql status  # 查看状态

systemctl start mysql
systemctl stop mysql
systemctl restart mysql
systemctl status mysql

二、连接MySQL

语法：

$> mysql -h host -u user -p
Enter password: ********

如：

[nosee@instance-4 /]$ mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.27 MySQL Community Server - GPL

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> exit;
Bye
[nosee@instance-4 /]$ 

三、SQL语句

SQL语句的分类：DDL、DML、DQL、DCL

• DDL（Data Definition Language）数据定义语言
  用来定义数据库对象：数据库、表、列等。关键词：create、drop、alter等
• DML（Data Manipulation Language）数据操作语言
  用来对数据库中表的数据进行增删改。关键词：insert、delete、update等
• DQL（Data Query Language）数据查询语言
  用来查询数据库中表的数据。关键词：select、where等
• DCL（Data Control Language）数据控制语言
  用来定义数据库的访问权限``和安全级别，及创建用户。关键词：grant、revoke等

四、查看帮助

mysql> help contents;
You asked for help about help category: "Contents"
For more information, type 'help <item>', where <item> is one of the following
categories:
   Account Management
   Administration
   Components
   Compound Statements
   Contents
   Data Definition
   Data Manipulation
   Data Types
   Functions
   Geographic Features
   Help Metadata
   Language Structure
   Loadable Functions
   Plugins
   Prepared Statements
   Replication Statements
   Storage Engines
   Table Maintenance
   Transactions
   Utility

mysql>

五、参考

8.0官方文档：https://dev.mysql.com/doc/refman/8.0/en/