Centos7.6安装MySQL(超详细)

1、查看是否已经安装Mysql

rpm -qa | grep mysql

我已经安装过了

[root@localhost ~]# rpm -qa | grep mysql
bt-mysql57-5.7.37-1.el7.x86_64

如果你查看出来有东西，可以使用下面命令将其删除

rpm -e 文件名

[root@localhost ~]# rpm -e bt-mysql57-5.7.37-1.el7.x86_64

如果提示warning: waiting for transaction lock on /var/lib/rpm/.rpm.lock，则需要执行

[root@localhost ~]# rm -f /var/lib/rpm/.rpm.lock

2、下载官方Mysql包

wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm

[root@localhost ~]# wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
--2022-06-09 13:25:18--  http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
Resolving dev.mysql.com (dev.mysql.com)... 137.254.60.11
Connecting to dev.mysql.com (dev.mysql.com)|137.254.60.11|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: https://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm [following]
--2022-06-09 13:25:19--  https://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
Connecting to dev.mysql.com (dev.mysql.com)|137.254.60.11|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://repo.mysql.com//mysql57-community-release-el7-10.noarch.rpm [following]
--2022-06-09 13:25:21--  https://repo.mysql.com//mysql57-community-release-el7-10.noarch.rpm
Resolving repo.mysql.com (repo.mysql.com)... 96.17.188.242
Connecting to repo.mysql.com (repo.mysql.com)|96.17.188.242|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 25548 (25K) [application/x-redhat-package-manager]
Saving to: ‘mysql57-community-release-el7-10.noarch.rpm’
​
100%[============================================================================>] 25,548      38.5KB/s   in 0.6s   
​
2022-06-09 13:25:23 (38.5 KB/s) - ‘mysql57-community-release-el7-10.noarch.rpm’ saved [25548/25548]
​
-c: No such file or directory
No URLs found in -c.
FINISHED --2022-06-09 13:25:23--
Total wall clock time: 4.6s
Downloaded: 1 files, 25K in 0.6s (38.5 KB/s)
​

如果提示：-bash: wget: command not found则是未安装wget

可以通过yum -y install wget来安装

如果安装有提示：Cannot write to ‘mysql57-community-release-el7-10.noarch.rpm’ (No such file or directory)，那就是权限不够

可以输入 su root 来解决，然后重新下载。

3、安装MysQL包

yum -y install mysql57-community-release-el7-10.noarch.rpm

[root@localhost ~]# yum -y install mysql57-community-release-el7-10.noarch.rpm
Loaded plugins: fastestmirror
Examining mysql57-community-release-el7-10.noarch.rpm: mysql57-community-release-el7-10.noarch
Marking mysql57-community-release-el7-10.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql57-community-release.noarch 0:el7-10 will be installed
--> Finished Dependency Resolution
​
Dependencies Resolved
​
======================================================================================================================
 Package                          Arch          Version         Repository                                       Size
======================================================================================================================
Installing:
 mysql57-community-release        noarch        el7-10          /mysql57-community-release-el7-10.noarch         30 k
​
Transaction Summary
======================================================================================================================
Install  1 Package
​
Total size: 30 k
Installed size: 30 k
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Warning: RPMDB altered outside of yum.
  Installing : mysql57-community-release-el7-10.noarch                                                            1/1 
  Verifying  : mysql57-community-release-el7-10.noarch                                                            1/1 
​
Installed:
  mysql57-community-release.noarch 0:el7-10                                                                           
​
Complete!
​

4、安装MySQL

yum -y install mysql-community-server

[root@localhost ~]# yum -y install mysql-community-server
​

如果执行命令过程中提示：Failing package is: mysql-community-client-5.7.38-1.el7.x86_64 GPG Keys are configured as: file://则是因为MySQL GPG秘钥过期导致

执行命令解决

rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

如果执行命令过程中提示：Unable to find a match: mysql-community-server

则可以通过命令解决

yum module disable mysql

5、 启动 Mysql 服务

systemctl start mysqld.service

如果没有报错，进入第六步，

如果执行报错，多半是没有权限，执行下面语句赋予权限，然后重试

chown mysql:mysql -R /var/lib/mysql

6、查看Mysql运行状态

service mysqld status

7、查看初始密码（localhost:后面为初始密码）

[root@localhost mysql]# grep 'password' /var/log/mysqld.log
2022-06-09T05:55:28.006431Z 1 [Note] A temporary password is generated for root@localhost: pjMts,Aa3Yr,

如果能正常查看到，则OK；如果查看不到，则表示没有密码。

8 进入数据库

mysql -u root -p

输入命令后，点击回车，会让你输入密码，然后输入刚刚的初始密码（输密码的时候不可见），当然支持粘贴，你可以复制初始密码后，然后粘贴。如果没有密码，直接回车即可。

[root@localhost mysql]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.38
​
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
​
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> 

注: 如果显示数据库无法访问

修改MySql配置文件my.cnf，新增skip-grant-tables

find / -name my.cnf

[root@localhost mysql]# find / -name my.cnf
/etc/my.cnf

修改文件之前记得先关闭mysql服务

service mysqld stop

通过 vi 指令进入文件

[root@localhost mysql]# vi /etc/my.cnf

新增skip-grant-tables ,添加skip-grant-tables，这样mysql可以免密登录。

重启服务

service mysqld start

再次连接MySql,任意密码就可以进入了

mysql -u root -p

通过show databases;注意带;号可以查看数据库

mysql> show databases
    -> ;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

若出现此提示：ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement则需要去修改初始化的密码

重置密码为root，此命令适用于修改当前用户的密码

alter user user() identified by 'root'

mysql> alter user user() identified by 'root';
Query OK, 0 rows affected (0.00 sec)

如果执行命令时出现错误：ERROR 1819 (HY000): Your password does not satisfy the current policy requirements

则执行下方命令

mysql> set global validate_password_policy=LOW;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_length=4;
Query OK, 0 rows affected (0.00 sec)

修改配置文件my.cnf，删除skip-grant-tables

重启服务

service mysqld start

根据指令进入MySQL数据库

mysql -uroot -p

再次使用新密码登录即可！

TIPS:如果本地访问Linux数据库失败，则记得看下下面配置是否OK

1、服务器的防火墙mysql端口3306是否开放

1、查看防火墙是否开放3306端口
[root@localhost mysql]# firewall-cmd --query-port=3306/tcp
no
2、设置3306端口为永久开放
[root@localhost mysql]# firewall-cmd --add-port=3306/tcp --permanent
success
3、查看firewalld状态，发现当前状态为dead则表示为开启
[root@localhost mysql]# systemctl status firewalld
4、关闭防火墙
[root@localhost mysql]# systemctl stop firewalld
5、开启防火墙（设置了新的端口记得先关闭，在重启）
[root@localhost mysql]# systemctl start firewalld
​

2、如果提示如下，则表示没有允许远程登录

解决办法：

登录服务器上的mysql数据库，执行一下命令
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> update user set host = '%' where user = 'root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0
​
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
​