centos7+mysql5.7安装教程+（可能出现的多种错的解决办法）

#卸载系统自带的Mariadb

[root@master ~]# rpm -qa|grep mariadb
mariadb-libs-5.5.44-2.el7.centos.x86_64
[root@master ~]# rpm -e --nodeps mariadb-libs-5.5.44-2.el7.centos.x86_64

#检查mysql是否存在

[root@master ~]# rpm -qa | grep mysql
[root@master ~]#

#下载MySQL压缩包

点击打开链接

#解压并并改名为mysql，在此文件夹下新建data目录

[root@master apps]# tar -zxvf mysql-5.7.22-linux-glibc2.12-x86_64.tar.gz 
[root@master apps]# mv mysql-5.7.22-linux-glibc2.12-x86_64 mysql
[root@master apps]# cd mysql
[root@master apps]# mkdir data

#在etc下新建配置文件my.cnf，并在该文件内添加以下配置

[root@master ~]#vi /etc/my.cnf

[mysql]
#设置mysql客户端默认字符集
default-character-set=utf8 
[mysqld]
skip-name-resolve
#设置3306端口
port = 3306 
# 设置mysql的安装目录
basedir=/apps/mysql/
# 设置mysql数据库的数据的存放目录
datadir=/apps/mysql/data
# 允许最大连接数
max_connections=200
# 服务端使用的字符集默认为8比特编码的latin1字符集
character-set-server=utf8
# 创建新表时将使用的默认存储引擎
default-storage-engine=INNODB 
lower_case_table_names=1
max_allowed_packet=16M
log-error = /apps/mysql/data/error.log
pid-file = /apps/mysql/data/mysql.pid
user = root
tmpdir = /tmp
socket = /tmp/mysql.sock

#安装和初始化

[root@master ~]cd /apps/mysql
[root@master mysql]bin/mysql_install_db --user=root --basedir=/apps/mysql --datadir=/apps/mysql/data
[root@master mysql]cp ./support-files/mysql.server /etc/init.d/mysqld
[root@master mysql]chown 777 /etc/my.cnf 
[root@master mysql]chmod +x /etc/init.d/mysqld

#启动服务

[root@master mysql]# /etc/init.d/mysqld start
Starting MySQL. SUCCESS! 

#查看端口运行情况（3306）
[root@master mysql]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      1/systemd           
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN      1326/dnsmasq        
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      983/sshd            
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      986/cupsd           
tcp6       0      0 :::111                  :::*                    LISTEN      1/systemd           
tcp6       0      0 :::22                   :::*                    LISTEN      983/sshd            
tcp6       0      0 ::1:631                 :::*                    LISTEN      986/cupsd           
tcp6       0      0 :::3306                 :::*                    LISTEN      16421/mysqld 

#登录MySQL

#查看生成的初始密码
[root@master mysql]# cat /root/.mysql_secret 
# Password set for user 'root@localhost' at 2018-07-06 10:36:35 
#Lws4rXsnhbA

#密码登录（可能会报错）
[root@master mysql]# mysql -u root -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

#如果登录成功，显示成这样
[root@master ~]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.22 MySQL Community Server (GPL)

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.

mysql> 

============================================================================

#安装过程中可能出现的错误

错误1：解决严格按照下面配置进行（/tmp/mysql.sock）位置至关重要

ERROR! The server quit without updating PID file

[root@master mysql]# /etc/init.d/mysqld start
Starting MySQL.Logging to '/apps/mysql/data/master.hadoop.err'.
 ERROR! The server quit without updating PID file (/apps/mysql/data/master.hadoop.pid)

[mysql]
# 设置mysql客户端默认字符集
default-character-set=utf8 
[mysqld]
skip-name-resolve
#设置3306端口
port = 3306 
# 设置mysql的安装目录
basedir=/apps/mysql/
# 设置mysql数据库的数据的存放目录
datadir=/apps/mysql/data
# 允许最大连接数
max_connections=200
# 服务端使用的字符集默认为8比特编码的latin1字符集
character-set-server=utf8
# 创建新表时将使用的默认存储引擎
default-storage-engine=INNODB 
lower_case_table_names=1
max_allowed_packet=16M
log-error = /apps/mysql/data/error.log
pid-file = /apps/mysql/data/mysql.pid
user = root
tmpdir = /tmp
socket = /tmp/mysql.sock

然后：删除data目录中的所有文件，重新初始化

[root@master mysql]# rm -rf data/*

[root@master mysql]# bin/mysql_install_db --user=mysql --basedir=/apps/mysql/ --datadir=/apps/mysql/data/

错误2：（mysql_install_db: [ERROR] Found option without preceding group in config file /etc/my.cnf at line 1!）

[root@master mysql]# bin/mysql_install_db --user=mysql --basedir=/apps/mysql/ --datadir=/apps/mysql/data/
mysql_install_db: [ERROR] Found option without preceding group in config file /etc/my.cnf at line 1!
mysql_install_db: [ERROR] Fatal error in defaults handling. Program aborted!

[root@master mysql]# vi /etc/my.cnf(该文件有语法错误，修改)

============================================================================

#如果再登录中出现了问题

#查看生成的初始密码
[root@master mysql]# cat /root/.mysql_secret 
# Password set for user 'root@localhost' at 2018-07-06 10:36:35 
#Lws4rXsnhbA

#密码登录（可能会报错）
[root@master mysql]# mysql -u root -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

解决办法：

[root@master mysql]# service mysqld stop
Shutting down MySQL.. SUCCESS! 

#报错解决方法
[root@master mysql]# vi /etc/my.cnf
在[mysqld]的段中加上一句：skip-grant-tables 保存并且退出vi。

[root@master mysql]# service mysqld start
Starting MySQL. SUCCESS! 
[root@master mysql]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.22 MySQL Community Server (GPL)

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.

mysql> 

登录并修改MySQL的root密码
mysql> USE mysql ; 
mysql> update user set password=password("*******") where user="*******";  #修改密码报错
ERROR 1054 (42S22): Unknown column 'password' in 'field list'
mysql> update mysql.user set authentication_string=password('*******') where user='*******';  #修改密码成功
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1 
mysql> flush privileges ; 
mysql> exit

# vi /etc/my.cnf
将刚才在[mysqld]的段中加上的skip-grant-tables删除 
保存并且退出vi。

重新启动mysqld 

登陆后重要的一步

否则报错：ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

解决办法：

安装完mysql 之后，登陆以后，不管运行任何命令，总是提示这个
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

step 1: SET PASSWORD = PASSWORD('your new password');

step 2: ALTER USER 'root'@'localhost' PASSWORD EXPIRE NEVER;

step 3: flush privileges;

完成以上三步退出再登，使用新设置的密码就行了，后两部原样设置即可

mysql> SET PASSWORD = PASSWORD('******');
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> ALTER USER 'root'@'localhost' PASSWORD EXPIRE NEVER;
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show databases
    -> ;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

mysql> exit
Bye
[root@master ~]#