要以管理员的身份运行cmd
1.下载mysql解压缩版本
http://dev.mysql.com/downloads/mysql/
2.解压缩本地目录(我的是F盘)
3.在根目录下建立my.ini文件内容：
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.
[client]
default-character-set=utf8
[mysqld]
character_set_server=utf8
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
# These are commonly set, remove the # and set as required.
basedir = "F:\mysql-5.7.12-winx64"
datadir = "F:\mysql-5.7.12-winx64\data"
tmpdir = "F:\mysql-5.7.12-winx64\data"
socket = "F:\mysql-5.7.12-winx64\data\mysql.sock"
port = 3306
log-error = "F:\mysql-5.7.12-winx64\data\mysql_error.log"
# server_id = .....
max_connections = 100
table_open_cache = 256
query_cache_size = 1M
tmp_table_size = 32M
thread_cache_size = 8
innodb_data_home_dir = "F:\mysql-5.7.12-winx64\data\"
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 128M
innodb_buffer_pool_size = 128M
innodb_log_file_size = 10M
innodb_thread_concurrency = 16
innodb-autoextend-increment = 1000
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
join_buffer_size = 128M
sort_buffer_size = 32M
read_rnd_buffer_size = 32M
max_allowed_packet = 32M
explicit_defaults_for_timestamp = true
sql_mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
4.最新版本的mysql，要初始化，初始化代码如下：
mysqld --initialize-insecure （前提是要配置mysql的bin目录到环境变量里边，如果不配置的话，要切换到mysql的bin目录下）
以上代码将会生成一个没有密码的root用户，如果不加-insecure那么root用户的密码是随机生成到，到存在
log-error = "F:\mysql-5.7.12-winx64\data\mysql_error.log"
5.把mysql添加到服务中：
mysqld --install mysql //添加
//mysqld --remove mysql 删除
6.启动服务
net start mysql
//net stop mysql 停止服务
7.连接数据库
mysql -uroot -p
//此时的密码为空
8.修改数据库密码为：admin123
use mysql;
set password = password("admin123")