Oracle官方版MySQL安装(CentOS/Redhat)

el7系列

wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
rpm -ivh mysql57-community-release-el7-11.noarch.rpm

el6系列

wget https://dev.mysql.com/get/mysql57-community-release-el6-11.noarch.rpm
rpm -ivh mysql57-community-release-el6-11.noarch.rpm

切换repo的5.5/5.6/5.7版本

sudo yum-config-manager --disable mysql57-community
sudo yum-config-manager --enable mysql56-community

刷新repo

yum makecache

启动服务

sudo service mysqld start
sudo systemctl start mysqld.service

查看服务

sudo service mysqld status
sudo systemctl status mysqld.service

5.7版本修改初始密码

sudo grep 'temporary password' /var/log/mysqld.log

mysql -uroot -p

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!';

5.6版本修改初始密码（因为在安装过程中设置了）

mysql_secure_installation

修改最大连接数

1.修改系统文件打开限制/etc/security/limits.conf
mysql hard nofile 65535
mysql soft nofile 65535
2.修改my.cnf
在[mysqld_safe]部分加入
max_connections=5000
3.修改/lib/systemd/system/mysqld.service
在[Service]部分加入
LimitCORE=infinity
LimitNOFILE=100001
LimitNPROC=100001
4.重载
systemctl daemon-reload
systemctl restart mysqld.service

开启MySQL远程访问权限 允许远程连接

1、登录服务器，然后运行命令：mysql -u root –p ，然后输入密码，该步骤是进入数据库。
2、mysql>use mysql;
3、授权：
例如想root使用123456从任何主机连接到mysql服务器：

mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;

如果想允许用户abc从ip为10.10.50.127的主机连接到mysql服务器,并使用654321作为密码：

mysql>GRANT ALL PRIVILEGES ON *.* TO 'abc'@'10.10.50.127' IDENTIFIED BY '654321' WITH GRANT OPTION;

4、刷新权限：

mysql>FLUSH PRIVILEGES;

PS：忘记密码怎么办

1.首先停止mysql服务器

service mysql stop  

2.使用--skip-grant-tables选项跳过授权表验证，
--skip-grant-tables Start without grant tables. This gives all users FULL
ACCESS to all tables.

使用--skip-grant-tables启动mysql服务器

mysqld --skip-grant-tables --user=mysql   

查看启动情况

ps -ef | grep mysql  
mysql    10209 14240  4 13:52 pts/0    00:00:00 mysqld --skip-grant-tables --user=mysql  
root     10229 14240  0 13:53 pts/0    00:00:00 grep mysql  

3.我们切换到mysql数据库下尝试

root@localhost[(none)]> use mysql     

4.尝试用password函数方式来更新password列

root@localhost[mysql]> update user set password=password('passwd') where user='root'; --此方式更新成功  
Query OK, 1 row affected (0.04 sec)  
Rows matched: 1  Changed: 1  Warnings: 0  

5.验证

root@localhost[mysql]> select host,user,password from user where user='root';    --可以看到密码已经变成了密文  
+-----------+------+-------------------------------------------+  
| host      | user | password                                  |  
+-----------+------+-------------------------------------------+  
| localhost | root | *59C70DA2F3E3A5BDF46B68F5C8B8F25762BCCEF0 |  
+-----------+------+-------------------------------------------+  

6.刷新权限

root@localhost[mysql]> flush privileges;  
Query OK, 0 rows affected (0.00 sec)

7.最好重启mysql