连接数据库：

打开MySQL命令窗口

• 在DOS命令行窗口
• 连接数据库语句 : mysql -h 服务器主机地址 -u 用户名 -p 用户密码

Microsoft Windows [版本 10.0.18363.657]
(c) 2019 Microsoft Corporation。保留所有权利。

C:\WINDOWS\system32>mysql -u root -p
Enter password: ******
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.7.19 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

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> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| indextest          |
| mysql              |
| performance_schema |
| school             |
| shop               |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

mysql> use school
Database changed
mysql> show tables;
+------------------+
| Tables_in_school |
+------------------+
| category         |
| grade            |
| result           |
| student          |
| subject          |
+------------------+
5 rows in set (0.00 sec)

mysql> describe student;
+--------------+--------------+------+-----+---------+-------+
| Field        | Type         | Null | Key | Default | Extra |
+--------------+--------------+------+-----+---------+-------+
| StudentNo    | int(4)       | NO   | PRI | NULL    |       |
| LoginPwd     | varchar(20)  | YES  |     | NULL    |       |
| StudentName  | varchar(20)  | YES  |     | NULL    |       |
| Sex          | tinyint(1)   | YES  |     | NULL    |       |
| GradeId      | int(11)      | YES  |     | NULL    |       |
| Phone        | varchar(50)  | NO   |     | NULL    |       |
| Address      | varchar(255) | NO   |     | NULL    |       |
| BornDate     | datetime     | YES  |     | NULL    |       |
| Email        | varchar(50)  | NO   | MUL | NULL    |       |
| IdentityCard | varchar(18)  | YES  | UNI | NULL    |       |
+--------------+--------------+------+-----+---------+-------+
10 rows in set (0.00 sec)

mysql> exit;
Bye

C:\WINDOWS\system32>

补充说明：所有的语句后面使用分号结尾

update user set password=password('******')where user='root'; 修改密码
flush privileges;  刷新数据库
show databases; 显示所有数据库
use dbname； 打开某个数据库
show tables; 显示数据库mysql中所有的表
describe user; 显示表mysql数据库中user表的列信息
create database name; 创建数据库
use databasename; 选择数据库
exit; 退出Mysql
? 命令关键词 : 寻求帮助
# 和 -- 表示注释

（1）结构化查询语句SQL

结构化查询语句分类 :

（2）命令行操作数据库

创建数据库 : create database [if not exists] 数据库名;

删除数据库 : drop database [if exists] 数据库名;

查看数据库 : show databases;

使用数据库 : use 数据库名;

CREATE DATABASE java;
DROP DATABASE IF EXISTS java;
CREATE DATABASE IF NOT EXISTS class01;
DROP DATABASE IF EXISTS	class01;
USE `class01` ;
SHOW DATABASES -- 查看所有的数据表