Debian 9安装mysql-server未提示root密码无法登录的解决问询

Hey there, let's work through this problem together— I’ve dealt with exactly these quirks on Debian 9 before, so I know the ins and outs here.

第一步：先无密码登录MySQL root账户 #

On Debian 9, when you install Oracle’s MySQL (not the default MariaDB), the root user is set up to use unix socket authentication by default instead of a password. That means you can log in directly with sudo without entering a password:

• Run this command in your terminal:

  sudo mysql -u root
  

You’ll be dropped right into the MySQL command-line console.

第二步：设置MySQL root账户的密码 #

Once you’re inside MySQL, let’s set a secure password for root and adjust the authentication method so you can log in with a password later:

1. First, switch to the mysql system database where user credentials are stored:

   USE mysql;
   

2. Update the root user’s password and switch to password-based authentication (you can keep socket auth too if you want, but this lets you log in with mysql -u root -p):

   ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'your-strong-password-here';
   

   Replace your-strong-password-here with a secure password of your choice.
3. Flush the privileges to apply the changes immediately:

   FLUSH PRIVILEGES;
   

4. Exit the MySQL console:

   EXIT;
   

Now you should be able to log in with mysql -u root -p by entering the password you just set.

第三步：解决mysql_secure_installation只针对MariaDB的问题 #

The issue here is that Debian 9 comes with MariaDB’s version of mysql_secure_installation pre-installed, and it’s probably prioritized in your system’s PATH over the MySQL version. Here’s how to fix it:

Option 1: Use the MySQL-specific mysql_secure_installation script #

First, find where MySQL’s version of the script lives:

find / -name mysql_secure_installation 2>/dev/null

If you installed MySQL via Oracle’s official repo, it’s likely in /usr/bin/ but you can confirm it’s the MySQL version by checking its ownership. Alternatively, if you did a binary install, it’ll be in /usr/local/mysql/bin/.

Run the script with sudo using its full path. For example:

sudo /usr/local/mysql/bin/mysql_secure_installation

Follow the prompts— it’ll now configure your MySQL instance’s security settings, not MariaDB’s.

Option 2: Manually apply the security steps (if the script still misbehaves) #

If you can’t get the right script to run, you can do exactly what mysql_secure_installation does manually in the MySQL console (log in with sudo mysql -u root first):

• Delete anonymous user accounts (these are a security risk):

  DROP USER ''@'localhost';
  

• Remove the test database (it’s unused and accessible to anonymous users by default):

  DROP DATABASE test;
  

• Prevent root from logging in remotely (unless you explicitly need this, it’s safer to disable):

  DROP USER 'root'@'%';
  

• Flush privileges again to save changes:

  FLUSH PRIVILEGES;
  

Bonus: Fix your PATH to prioritize MySQL #

To avoid this confusion in the future, add MySQL’s bin directory to the front of your system PATH. Edit your ~/.bashrc file:

nano ~/.bashrc

Add this line at the end (adjust the path if your MySQL bin is in a different location):

export PATH=/usr/local/mysql/bin:$PATH

Save and exit, then reload your bash profile:

source ~/.bashrc

Now when you run mysql_secure_installation, it’ll use the MySQL version by default.

Let me know if you run into any issues with these steps— I’m happy to help troubleshoot further!

内容的提问来源于stack exchange，提问作者tommy716