CentOS7 installing MySQL

MARIADB is installed by default in CentOS, this is the branch of MySQL, but in order to need, it is necessary to install MySQL in the system, and after the installation is complete, you can overwrite the mariadb directly.

1 Download and install the official MySQL Yum Repository

[Email protected] ~]# Wget-i-C http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm

Use the command above to download the installation of Yum Repository, about 25KB, then you can directly install Yum.

[Email protected] ~]# yum-y install mysql57-community-release-el7-10.noarch.rpm

After that, the MySQL server starts to install.

[Email protected] ~]# yum-y install Mysql-community-server

This step may take some time, and the previous mariadb will be overwritten when the installation is complete.

Now that MySQL is installed, then there are some settings for MySQL.

2 MySQL Database settings

Start MySQL First

[Email protected] ~]# systemctl start  mysqld.service

View MySQL running status, running status

[Email protected] ~]# systemctl status Mysqld.service

At this point, MySQL has started to run normally, but to get into MySQL also need to find the root user's password, the following command can be found in the log file password:

[[email protected] ~]# grep "Password"/var/log/mysqld.log

Enter the database as follows:

[Email protected] ~]# mysql-uroot-p

Enter the initial password and you can't do anything at this time, because MySQL must change the password before you can manipulate the database:

Mysql> ALTER USER ' root ' @ ' localhost ' identified by ' new password ';

Here is a question, if the setting of the new password is too simple to error:

The reason for this is that MySQL has a password-setting specification, specifically related to the value of Validate_password_policy:

MySQL complete initial password rules can be viewed by the following commands:

mysql> SHOW VARIABLES like ' validate_password% '; +--------------------------------------+-------+| Variable_name                        | Value |+--------------------------------------+-------+| Validate_password_check_user_name    | OFF   | | 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)

The length of the password is determined by validate_password_length, while the Validate_password_length formula is:

Validate_password_length = Validate_password_number_count + Validate_password_special_char_count + (2 * validate_ Password_mixed_case_count)

Mine is already modified, the first value of the initial case is On,validate_password_length is 8. Can be modified by the following command:

Mysql> set global validate_password_policy=0;mysql> set global validate_password_length=1;

After the setting is I found above the values, at this time the password can be set up very simple, such as 1234. The password settings to this database are complete.

But at this point, there is a problem, because the Yum Repository is installed, each time the Yum operation will be automatically updated, you need to uninstall this:

[Email protected] ~]# yum-y Remove Mysql57-community-release-el7-10.noarch

This is really done.

CentOS7 installing MySQL