在使用mysql 数据库之前，我们要先做一些简单的设置，比如 设置root用户密码，禁止匿名登录啊之类的，下面的初始化需要在mysql已经启动了的状态下才能进行。
    Mysql 5.6版本初始化：
    输入命令：
    [root@web01 ~]# /app/mysql/bin/mysql_secure_installation

    NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MySQL
    SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!

    In order to log into MySQL to secure it, we’ll need the current
    password for the root user. If you’ve just installed MySQL, and
    you haven’t set the root password yet, the password will be blank,
    so you should just press enter here.

    Enter current password for root (enter for none): <=这里按回车
    OK, successfully used password, moving on…

    Setting the root password ensures that nobody can log into the MySQL
    root user without the proper authorisation.

    Set root password? [Y/n] y <=询问是否设置root密码，我们输入y回车后给root设置密码
    New password: admin
    Re-enter new password: admin
    Password updated successfully!
    Reloading privilege tables..
    … Success!

    By default, a MySQL installation has an anonymous user, allowing anyone
    to log into MySQL without having to have a user account created for
    them. This is intended only for testing, and to make the installation
    go a bit smoother. You should remove them before moving into a
    production environment.

    Remove anonymous users? [Y/n] y <=询问是否删除匿名用户，我们输入y回车
    … Success!

    Normally, root should only be allowed to connect from ‘localhost’. This
    ensures that someone cannot guess at the root password from the network.

    Disallow root login remotely? [Y/n] n <=询问是否禁止root账号远程登录，我们输入n
    … skipping.

    By default, MySQL comes with a database named ‘test’ that anyone can
    access. This is also intended only for testing, and should be removed
    before moving into a production environment.

    Remove test database and access to it? [Y/n] y <=询问是否删除测试数据库，输入y
    - Dropping test database…
    … Success!
    - Removing privileges on test database…
    … Success!

    Reloading the privilege tables will ensure that all changes made so far
    will take effect immediately.

    Reload privilege tables now? [Y/n] y <=询问是否重新载入权限信息，输入y
    … Success!

    Cleaning up…

    All done! If you’ve completed all of the above steps, your MySQL
    installation should now be secure.

    Thanks for using MySQL! <=看到这里提示所以操作都已经成功完成了。

    Mysql 5.7版本初始化：
    ./mysqld --user=mysql --basedir=/app/mysql --datadir=/data/mysql/data --initialize