centos7 安装 mysql

1.创建相关目录
    Mysql目录安装位置：/usr/local/mysql
    数据库保存位置：/data/mysql         必须创建 不然会报错
    日志保存位置：/data/log/mysql      必须创建 不然会报错
    安装必要组件：yum -y install gcc*  libaio  重要
    关闭防火墙                       重要，不然外部没办法访问mysql
    mysql 启动、重启命令：service mysql start       后面没有带d
    mysql配置文件所在位置：/etc/my.cnf 
    mysql启动文件所在位置：/etc/init.d/mysql
2.下载mysql
    选择社区版，然后选择 mysql 版本 选择 linux 通用版
    可以直接使用 wget 下载

    下载完成以后，解压到 /usr/local/  目录下 将文件名修改为 mysql

    

3.创建 mysql 用户和mysql组
    useradd mysql
    groupadd mysql
4.改变mysql安装目录所有者
    cd /usr/local/mysql
    chown -R mysql .    (注意后面还有个点)  改变目录所有
    chgrp -R mysql .    改变目录所有组

5.配置参数
    cd /usr/local/mysql
    bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql

    

    此处需要注意记录生成的临时密码，如上文：YLi>7ecpe;YP
    bin/mysql_ssl_rsa_setup  --datadir=/data/mysql

6.修改mysql配置文件和mysql启动文件
    cd  /usr/local/mysql/support-files
    cp my-default.cnf /etc/my.cnf           ( mysql 配置文件 )
    cp mysql.server /etc/init.d/mysql       ( mysql 启动脚本 )

    
    vim /etc/init.d/mysql   修改mysql启动文件

    vim /etc/my.cnf         修改mysql配置文件

    

# 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]
port = 3306
socket = /usr/local/mysql/mysql.sock
# character-set-server = utf8

[mysql]
no-auto-rehash

[mysqld]

# 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 = .....
# datadir = .....
# port = .....
# server_id = .....
# socket = .....
socket = /usr/local/mysql/mysql.sock
basedir = /usr/local/mysql
max_allowed_packet = 32M
datadir = /data/mysql
explicit_defaults_for_timestamp = true
skip-ssl
secure-file-priv = NULL
lower_case_table_names = 1
back_log = 300
max_connections = 3000
max_connect_errors = 100
table_open_cache = 4096
external-locking = FALSE
max_allowed_packet = 32M
sort_buffer_size = 16M
join_buffer_size = 16M
thread_cache_size = 16
query_cache_size = 128M
query_cache_limit = 4M
ft_min_word_len = 8
thread_stack = 512K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 128M
max_heap_table_size = 128M

###*** slow query parameters
long_query_time = 6
slow_query_log
slow_query_log_file = /data/log/mysql/slow.log

[mysqldump]
quick
max_allowed_packet = 32M

[mysqld_safe]
open-files-limit = 8192
log-error=/data/log/mysql/mysql_3306.err


# 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 = 2M
# read_rnd_buffer_size = 2M 

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES 

7.启动mysql
    cd /usr/local/mysql
    bin/mysqld_safe --user=mysql &  (启动mysql)
    bin/mysql --user=root –p            (输入第5步生成的临时密码)

    此时会成功进入mysql
    mysql> set password=password('root');           (将root帐户密码设为root)
    mysql>grant all privileges on *.* to root@'%' identified by 'root';  (允许root执行所有命令)
    mysql> flush privileges;        (立刻生效)
8.将 mysql 命令 添加到环境变量
    vim /etc/profile
    添加：export PATH=/usr/local/mysql/bin:$PATH

    

    source /etc/profile    ( 添加的环境变量立刻生效 )
9.开机启动mysql
    chmod 755 /etc/init.d/mysql
    chkconfig --add mysql
    chkconfig --level 345 mysql on