Centos7安装Mysql

一 mysql下载

地址： https://dev.mysql.com/downloads/mysql/#downloads

二在centos7上创建安装文件存放、解压目录，上传文件并解压

创建目录：mkdir /usr/local/mysql

上传文件：（使用Xftp）...

解压文件：tar -zxvf mysql-5.7.19-linux-glibc2.12-x86_64.tar.gz -C /usr/local/mysql/

修改文件名称：

cd /usr/local/mysql/

mv mysql-5.7.19-linux-glibc2.12-x86_64 mysql

当前目录：/usr/local/mysql

命令：cd mysql

创建文件的目录：/usr/local/mysql/mysql

命令：mkdir data

四创建用户及组

创建组：   groupadd mysql  

创建用户： useradd -r -g mysql mysql

五将mysql及其下所有的目录所有者和组均设为mysql

命令：chown mysql:mysql -R .

六初始化数据库

/usr/local/mysql/mysql/bin/mysqld --initialize --user=mysql --datadir=/usr/local/mysql/mysql/data --basedir=/usr/local/mysql/mysql

初始化成功之后会出现默认的root用户密码，如下图

七创建修改my.cnf文件

这个版本和别的版本安装最大的区别就是别的版本在mysql/support-files下有my-default.cnf文件，别的版本只需要将my-default.cnf文件拷贝到/etc目录下即可，而这个版本需要自己创建my.cnf文件.

因此我们

vi /etc/my.cnf

把下面内容粘进去即可，标红的地方是需要注意的。　

（注）：确保全部复制粘贴文件　

# 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.
# 组

[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

general_log_file = /var/log/mysql/mysql.log

general_log = 1

# These are commonly set, remove the # and set as required.

basedir =/usr/local/mysql/mysql

datadir =/usr/local/mysql/mysql/data

port = 3306

#server_id = .....

socket =/usr/local/mysql/mysql/tmp/mysql.sock

#kip-external-locking

skip-name-resolve

pid-file=/usr/local/mysql/mysql/data/mysql.pid

character_set_server=utf8

init_connect='SET NAMES utf8'

log-error=/usr/local/mysql/mysql/data/mysqld.err

slow_query_log = 1

slow_query_log_file =/usr/local/mysql/mysql/data/slow-query.log

long_query_time = 1

log-queries-not-using-indexes

max_connections = 1024

back_log = 128

wait_timeout = 100

interactive_timeout = 200

key_buffer_size=256M

query_cache_size = 256M

query_cache_type=1

query_cache_limit=50M

max_connect_errors=20

sort_buffer_size = 2M

max_allowed_packet=16M

join_buffer_size=2M

thread_cache_size=200

innodb_buffer_pool_size = 2048M

innodb_flush_log_at_trx_commit = 1

innodb_log_buffer_size=32M

innodb_log_file_size=128M

innodb_log_files_in_group=3

server_id=1

log-bin=mysql-bin

binlog_cache_size=2M

max_binlog_cache_size=8M

max_binlog_size=512M

expire_logs_days=7

read_buffer_size=1M

read_rnd_buffer_size=16M

bulk_insert_buffer_size=64M

# 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

八创建tmp目录

mkdir /usr/local/mysql/mysql/tmp

九启动mysql

命令：cd  /usr/local/mysql/mysql/bin

命令：./mysqld_safe &

十登录数据库，密码为第六步生成的默认密码

./mysql -u root -p

十一操作数据库时报错

mysql> use mysql
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

在没有进行修改默认密码之前，是不允许做任何事情的。

解决方案：

SET PASSWORD = PASSWORD('123456');

十二错误处理以及使用SQLyog连接数据库

1 未关闭防火墙有可能造成数据库不能连接

(注)：centos7

systemctl stop firewalld.service #停止firewall

systemctl disable firewalld.service #禁止firewall开机启动

2（日志data/mysqld.err） mysqld: File '/var/log/mysql/mysql.log' not found (Errcode: 2 - No such file or directory)

解决方案：

查看是否有/var/log/mysql这个目录，没有的话创建

mkdir /var/log/mysql

目录：/var/log下执行权限修改命令

chown mysql:mysql -R .

3（日志data/mysqld.err）Could not create unix socket lock file /usr/local/mysql/mysql/tmp/mysql.sock.lock.

解决方案：

cd /usr/local/mysql/mysql/tmp/

chown -R mysql:mysql /usr/local/mysql/mysql/tmp/

4 （日志data/mysqld.err）Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

解决方案：(创建软连接)

ln -s /usr/local/mysql/mysql/tmp/mysql.sock /tmp/mysql.sock

5 host"..*.***" is not allowed to connect mysql--------mysql"Access denied for user'root'@'IP地址'"

解决方案：（注*用户名密码）

登录mysql给root用户授权

GRANT ALL PRIVILEGES ON *.* TO 'ROOT'@'%' IDENTIFIED BY '' WITH GRANT OPTION;

十三关闭mysql数据库

ps -A|grep mysql

kill -9 进程号

kill -9 进程号