redhat6.9安装 mysql 出现问题

问题1 ： MySQL Daemon failed to start.
 

解决方法： 

因为我之前安装过mysql。 现在虽然rpm 删除安装包，但是没有删除完全。

[root@redhat6 yao]# rm -rf /var/lib/mysql/*

再运行： service mysqld start 

正常运行

参考  ： https://blog.youkuaiyun.com/hwijew/article/details/79582230

问题2 ：

mysql> set password for 'root'@'localhost' = password('123456');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'password('123456')' at line 1
因为安装的是mysql 8.0.12 版本。不再支持该语句。

参考： https://www.jb51.net/article/142025.htm

解决方法： 

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 authentication_string='' where user='root';
Query OK, 1 row affected (0.04 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> alter user 'root'@'%' identified by '123456';
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

mysql> alter user 'root'@'%' identified with mysql_native_password by '123456';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
 

解决办法：

mysql> show variables like 'validate_password%'
    -> ;
+--------------------------------------+--------+
| Variable_name                        | Value  |
+--------------------------------------+--------+
| validate_password.check_user_name    | ON     |
| validate_password.dictionary_file    |        |
| validate_password.length             | 8      |
| validate_password.mixed_case_count   | 1      |
| validate_password.number_count       | 1      |
| validate_password.policy             | MEDIUM |
| validate_password.special_char_count | 1      |
+--------------------------------------+--------+
7 rows in set (0.01 sec)
 

认证密码长度为8 。安全级别为： modium 

mysql> set global validate_password.length =0;
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password.policy =0;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'validate_password%';
+--------------------------------------+-------+
| Variable_name                        | Value |
+--------------------------------------+-------+
| validate_password.check_user_name    | ON    |
| validate_password.dictionary_file    |       |
| validate_password.length             | 4     |
| validate_password.mixed_case_count   | 1     |
| validate_password.number_count       | 1     |
| validate_password.policy             | LOW   |
| validate_password.special_char_count | 1     |
+--------------------------------------+-------+
7 rows in set (0.01 sec)

mysql> alter user 'root'@'%' identified with mysql_native_password by '123456';
Query OK, 0 rows affected (0.19 sec)
 

问题3 。。 不能远程访问

参考： https://www.cnblogs.com/xyabk/p/8967990.html

mysql> create user 'yao'@'%' identified by '123456';

mysql> grant all on *.* to 'yao'@'%';
Query OK, 0 rows affected (0.00 sec)mysql> exit 
Bye

重启mysql服务
[root@redhat6 yao]# service mysqld restart
停止 mysqld：                                              [确定]
正在启动 mysqld：                                          [确定]

远程登录成功： 

[root@redhat7 yao]# mysql -h 192.168.1.63 -u yao -p
Enter password: