MySQL 8 带来了全新的体验，比如支持 NoSQL、JSON 等，拥有比 MySQL 5.7 两倍以上的性能提升。本文讲解如何在 Windows 下安装 MySQL 8，以及基本的 MySQL 用法。
下载
下载地址 https://dev.mysql.com/downloads/mysql/8.0.html。
本例为：MySQL Community Server 8.0.12。
解压
解压至安装目录，比如 D 盘根目录下。
本例为：D:\mysql-8.0.12-winx64。
创建 my.ini
my.ini 是 MySQL 安装的配置文件：
1[mysqld] 2# 安装目录 3basedir=D:\\mysql-8.0.12-winx64 4# 数据存放目录 5datadir=D:\\mysqlData\\data
my.ini放置在 MySQL 安装目录的根目录下。需要注意的是，要先创建D:\mysqlData目录。data目录是由 MySQL 来创建。
初始化安装
执行：
mysqld --defaults-file=D:\mysql-8.0.12-winx64\my.ini --initialize --console
控制台输出如下，说明安装成功：
1>mysqld --defaults-file=D:\mysql-8.0.12-winx64\my.ini --initialize --console 22018-08-20T16:14:45.287448Z 0 [System] [MY-013169] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe (mysqld 8.0.12) initializing of server in progress as process 5012 32018-08-20T16:14:45.289628Z 0 [ERROR] [MY-010457] [Server] --initialize specified but the data directory has files in it. Aborting. 42018-08-20T16:14:45.299329Z 0 [ERROR] [MY-010119] [Server] Aborting 52018-08-20T16:14:45.301316Z 0 [System] [MY-010910] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe: Shutdown complete (mysqld 8.0.12) MySQL Community Server - GPL. 6 7D:\mysql-8.0.12-winx64\bin>mysqld --defaults-file=D:\mysql-8.0.12-winx64\my.ini --initialize --console 82018-08-20T16:15:25.729771Z 0 [System] [MY-013169] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe (mysqld 8.0.12) initializing of server in progress as process 18148 92018-08-20T16:15:43.569562Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: L-hk!rBuk9-. 102018-08-20T16:15:55.811470Z 0 [System] [MY-013170] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe (mysqld 8.0.12) initializing of server has completed
其中，“L-hk!rBuk9-.”就是 root 用户的初始化密码。稍后可以做更改。
启动、关闭 MySQL server
执行mysqld就能启动 MySQL server，或者执行 mysqld --console可以看到完整的启动信息：
1>mysqld --console 22018-08-20T16:18:23.698153Z 0 [Warning] [MY-010915] [Server] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release. 32018-08-20T16:18:23.698248Z 0 [System] [MY-010116] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe (mysqld 8.0.12) starting as process 16304 42018-08-20T16:18:27.624422Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed. 52018-08-20T16:18:27.793310Z 0 [System] [MY-010931] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe: ready for connections. Version: '8.0.12' socket: '' port: 3306 MySQL Community Server - GPL.
关闭，可以执行 mysqladmin -u root shutdown。
使用 MySQL 客户端
使用 mysql 来登录，账号为 root，密码为“L-hk!rBuk9-.”：
1>mysql -u root -p 2Enter password: ************ 3Welcome to the MySQL monitor. Commands end with ; or \g. 4Your MySQL connection id is 11 5Server version: 8.0.12 6 7Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. 8 9Oracle is a registered trademark of Oracle Corporation and/or its 10affiliates. Other names may be trademarks of their respective 11owners. 12 13Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
执行下面的语句来改密码。其中“123456”即为新密码。
1mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456'; 2Query OK, 0 rows affected (0.13 sec)
MySQL 常用指令
显示已有的数据库：
1mysql> show databases; 2+--------------------+ 3| Database | 4+--------------------+ 5| information_schema | 6| mysql | 7| performance_schema | 8| sys | 9+--------------------+ 104 rows in set (0.08 sec)
创建新的数据库：
1mysql> CREATE DATABASE lite; 2Query OK, 1 row affected (0.19 sec)
使用数据库：
1mysql> USE lite; 2Database changed
建表：
建表执行：
1mysql> CREATE TABLE t_user (user_id BIGINT NOT NULL, username VARCHAR(20)); 2Query OK, 0 rows affected (0.82 sec)
查看表：
查看数据库中的所有表：
1mysql> SHOW TABLES; 2+----------------+ 3| Tables_in_lite | 4+----------------+ 5| t_user | 6+----------------+ 71 row in set (0.00 sec)
查看表的详情：
1mysql> DESCRIBE t_user; 2+----------+-------------+------+-----+---------+-------+ 3| Field | Type | Null | Key | Default | Extra | 4+----------+-------------+------+-----+---------+-------+ 5| user_id | bigint(20) | NO | | NULL | | 6| username | varchar(20) | YES | | NULL | | 7+----------+-------------+------+-----+---------+-------+ 82 rows in set (0.00 sec)
插入数据：
1mysql> INSERT INTO t_user(user_id, username) VALUES(1, '老卫'); 2Query OK, 1 row affected (0.08 sec)