mysql的安装

初始化

关闭防火墙

systemctl stop firewalld.service

systemctl disable firewalld.service

关闭selinux

sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config && setenforce 0

yum -y install libaio libgcc_s.so.1 libstdc++.so.6 net-tools perl

1、mysql下载地址

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

https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.26-1.el7.x86_64.rpm-bundle.tar

2、删除centos自带的mariadb包

rpm -qa|grep mariadb //查询出来已安装的mariadb

rpm -e --nodeps 文件名 //卸载mariadb,文件名为上述命令查询出来的文件

例如：

rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64

3、安装mysql

解压tar包

tar xvf mysql-5.7.26-1.el7.x86_64.rpm-bundle.tar

按照依赖关系依次安装rpm包 依赖关系依次为common--libs--client--server

rpm -ivh mysql-community-common-5.7.26-1.el7.x86_64.rpm

rpm -ivh mysql-community-libs-5.7.26-1.el7.x86_64.rpm

rpm -ivh mysql-community-client-5.7.26-1.el7.x86_64.rpm

rpm -ivh mysql-community-server-5.7.26-1.el7.x86_64.rpm

如果没有报错 就不用安装 net-tools perl numactl

安装service 包提示cat

[root@VM_0_16_centos mysql]# rpm -ivh mysql-community-server-5.7.26-1.el7.x86_64.rpm

warning: mysql-community-server-5.7.26-1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY

error: Failed dependencies:

libnuma.so.1()(64bit) is needed by mysql-community-server-5.7.26-1.el7.x86_64

libnuma.so.1(libnuma_1.1)(64bit) is needed by mysql-community-server-5.7.26-1.el7.x86_64

libnuma.so.1(libnuma_1.2)(64bit) is needed by mysql-community-server-5.7.26-1.el7.x86_64

yum install net-tools 输入 y q确定

安装 perl

yum install perl

安装numactl

yum install numactl

4、启动mysql

systemctl start mysqld.service 启动mysql

systemctl status mysqld.service 查看mysql状态

systemctl stop mysqld.service 关闭mysql

mysql初始密码

cat /var/log/mysqld.log |grep password

查看密码

[root@VM_0_16_centos mysql]# cat /var/log/mysqld.log |grep password

2020-04-09T06:16:51.252669Z 1 [Note] A temporary password is generated for root@localhost: 5Scr:#kp8Vt?

密码为： 5Scr:#kp8Vt? 注意没有空格

如果找不到mysql初始密码

mysql密码找回

方法一:

vi /etc/my.cnf

在[mysqld]下加上 skip-grant-tables，如：

[mysqld]

skip-grant-tables#skip-grant-tables 加在最上面

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

重启mysql

service mysqld restart

登陆mysql后就可以修改密码了

mysql -u root 可以直接登录 跳过输入密码

update mysql.user set authentication_string=PASSWORD('root') where User='root';

flush privileges;

然后改回my.cnf重启mysql。

密码设置成功之后 就不要设置下面的密码策略了 面得弄巧成拙血泪史!不提了.

5、mysql设置

修改mysql密码

ALTER USER 'root'@'localhost' IDENTIFIED BY 'root';

ALTER USER 'root'@'localhost' IDENTIFIED BY ‘root';

更改策略密码

set global validate_password_policy=0;

更改mysql有效密码长度：

set global validate_password_length=1;

退出mysql quit + 回车

mysql授予root用户远程访问权限：

grant all privileges on *.* to root@'%' identified by '123456';

grant all privileges on *.* to root@'%' identified by 'root';

刷新权限表

flush privileges;

grant all privileges on *.* to 'root'@ '172.20.222.3' identified by 'root';

如果无法授权解决办法

ERROR 3009 (HY000): Column count of mysql.user is wrong. Expected 45, found 43. Created with MySQL 5

ERROR 3009 (HY000): Column count of mysql.user is wrong. Expected 45, found 43. Created with MySQL 5的解决方案。

错误是由于你曾经升级过数据库，升级完后没有使用

mysql_upgrade升级数据结构造成的。

解决办法：

使用mysql_upgrade命令

root@localhost ~]# mysql_upgrade -u root -p 13456

再输入密码

root

现象

l.help_topic OK

mysql.host OK

mysql.innodb_index_stats OK

mysql.innodb_table_stats OK

mysql.ndb_binlog_index OK

mysql.plugin OK

mysql.proc OK

mysql.procs_priv OK

mysql.proxies_priv OK

mysql.server_cost OK

mysql.servers OK

mysql.slave_master_info OK

mysql.slave_relay_log_info OK

mysql.slave_worker_info OK

mysql.slow_log OK

mysql.tables_priv OK

mysql.time_zone OK

mysql.time_zone_leap_second OK

mysql.time_zone_name OK

mysql.time_zone_transition OK

mysql.time_zone_transition_type OK