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：
[mysqld]
# 安装目录
basedir=D:\\mysql-8.0.12-winx64
# 数据存放目录
datadir=D:\\mysqlData\\data
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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
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控制台输出如下，说明安装成功：
>mysqld --defaults-file=D:\mysql-8.0.12-winx64\my.ini --initialize --console
2018-08-20T16:14:45.287448Z 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
2018-08-20T16:14:45.289628Z 0 [ERROR] [MY-010457] [Server] --initialize specified but the data directory has files in it. Aborting.
2018-08-20T16:14:45.299329Z 0 [ERROR] [MY-010119] [Server] Aborting
2018-08-20T16:14:45.301316Z 0 [System] [MY-010910] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe: Shutdown complete (mysqld 8.0.12) MySQL Community Server - GPL.
D:\mysql-8.0.12-winx64\bin>mysqld --defaults-file=D:\mysql-8.0.12-winx64\my.ini --initialize --console
2018-08-20T16:15:25.729771Z 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
2018-08-20T16:15:43.569562Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: L-hk!rBuk9-.
2018-08-20T16:15:55.811470Z 0 [System] [MY-013170] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe (mysqld 8.0.12) initializing of server has completed
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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：
>mysqld --console
2018-08-20T16:18:23.698153Z 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.
2018-08-20T16:18:23.698248Z 0 [System] [MY-010116] [Server] D:\mysql-8.0.12-winx64\bin\mysqld.exe (mysqld 8.0.12) starting as process 16304
2018-08-20T16:18:27.624422Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2018-08-20T16:18:27.793310Z 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.
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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-.”：
>mysql -u root -p
Enter password: ************
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 8.0.12
Copyright (c) 2000, 2018, 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.
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执行下面的语句来改密码。其中“123456”即为新密码。
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.13 sec)
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MySQL 常用指令
显示已有的数据库：
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.08 sec)
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创建新的数据库：
mysql> CREATE DATABASE lite;
Query OK, 1 row affected (0.19 sec)
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使用数据库：
mysql> USE lite;
Database changed
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建表：
建表执行：
mysql> CREATE TABLE t_user (user_id BIGINT NOT NULL, username VARCHAR(20));
Query OK, 0 rows affected (0.82 sec)
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查看表：
查看数据库中的所有表：
mysql> SHOW TABLES;
+----------------+
| Tables_in_lite |
+----------------+
| t_user |
+----------------+
1 row in set (0.00 sec)
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查看表的详情：
mysql> DESCRIBE t_user;
+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| user_id | bigint(20) | NO | | NULL | |
| username | varchar(20) | YES | | NULL | |
+----------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
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插入数据：
mysql> INSERT INTO t_user(user_id, username) VALUES(1, '老卫');
Query OK, 1 row affected (0.08 sec)
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