mysql delete user password

MySQL is a widely used relational database management system that allows users to create, manage and operate databases. In MySQL, administrators can create multiple users and assign different permissions to each user, such as only allowing queries or allowing reading and writing.

However, in some cases, an administrator may need to remove a user's access rights or delete the user entirely. This article will introduce how to delete users and their passwords in MySQL.

Delete user

In MySQL, we can delete a user through the following command:

DROP USER 'username'@'localhost';

Here, username represents the user of the user to be deleted name, localhost represents the host name of the user. If the user you want to delete is on a remote host, you need to use the corresponding host name. It should be noted that only users with CREATE USER and DROP USER permissions can delete other users.

If you are not sure which host the user you want to delete is on, please use the following command to query:

SELECT User, Host FROM mysql.user;

This will display all users of the MySQL installation, and the host they are on.

Delete users and keep their data

If you want to delete a user account, but want to keep the account data, you can use the following command:

DROP USER 'username'@'localhost' RESTRICT;

This command will delete the user, But keep its database and tables. This allows administrators to recreate users and connect them back to their previous data.

Delete a user and its data

If you want to delete a user and all its data, you can use the following command:

DROP USER 'username'@'localhost' CASCADE;

This command will delete the data stored under that user all databases and tables, and delete the user and his password. This is a strict warning to administrators because once the password is deleted, the user cannot be used again.

Delete user password

If you don’t want to completely delete the user, but want to delete the user’s password, you can use the following command:

UPDATE mysql.user SET authentication_string='' WHERE User='username' AND Host='localhost';

This command will change the username to username, the password of the user whose host is localhost is set to an empty string, which will allow the user to log in to the system, but will require a password because the password field is empty.

The value of the password field is stored in encrypted form, so you need to make sure to back up the database before performing this operation.

If you want to restore a user's permissions to their default values, you can use the following command:

FLUSH PRIVILEGES;

This command will immediately refresh the MySQL permissions table and make the changes take effect.

Summary

In MySQL, administrators can delete users, delete users and their data or just delete user passwords. This allows administrators to easily manage users and ensure the security of the system. Deleting users and their data is dangerous, so do it with caution and make a backup before doing so.

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