Administering User Accounts and Privileges in MySQL
Jul 10, 2025 pm 01:22 PM
Creating, managing and deleting MySQL users and permissions must follow the principle of minimum permissions to ensure security. 1. Create a user to use CREATE USER and specify the host and password plug-in; 2. Assign SELECT, INSERT and other permissions as needed when granting permissions, and use FLUSH PRIVILEGES to take effect; 3. Recycle permissions or reset permissions through REVOKE; 4. Delete users to use DROP USER to clean up in time to reduce risks; at the same time pay attention to the compatibility issues of remote access protection and client.
Managing MySQL user accounts and permissions is actually not complicated, but many people who are new to database operations and maintenance are prone to traps in this area. The key is to understand the basic logic of the permission system and how to allocate account permissions safely and effectively.
Create a user: Start with the basics
MySQL user account consists of a user name and a host name, in the format 'user'@'host' . Creating a user statement is also very simple:
CREATE USER 'new_user'@'localhost' IDENTIFIED BY 'password';
If you want this user to log in from any IP, you can change localhost to % :
CREATE USER 'remote_user'@'%' IDENTIFIED BY 'secure_password';
However, it should be noted that while allowing remote access, you must also ensure that your MySQL service is protected by firewalls, otherwise it will be easily attacked.
In addition, MySQL 8.0 has started to use the caching_sha2_password plug-in by default for authentication, and some old clients may not support it. If you encounter connection problems, you can manually specify mysql_native_password :
CREATE USER 'old_client_user'@'%' IDENTIFIED WITH mysql_native_password BY 'pass123';
Assign permissions: on-demand authorization, minimized principle
When granting permissions to users, it is recommended to follow the principle of "minimum permissions" and only open necessary permissions to avoid the risks brought about by excessive authorization.
Common permissions include:
-
SELECT: Query data -
INSERT: Insert data -
UPDATE: Update data -
DELETE: Delete data -
CREATE: Create a table or database -
DROP: Delete tables or databases -
GRANT OPTION: Grant or revoke permissions from other users
For example, if you want a user to only operate tables in a certain database, you can authorize it like this:
GRANT SELECT, INSERT ON mydb.* TO 'limited_user'@'%';
Don't forget to refresh the permissions after executing the permissions:
FLUSH PRIVILEGES;
Sometimes you will find that the permissions are not effective, it may be because you forgot to refresh, or it may be because the scope of the permissions is incorrect (for example, you gave permissions to a certain library, but the user used another library).
Modification and recycling permissions: Flexible adjustment
As business changes, user permissions also need to be adjusted dynamically. You can use GRANT to increase permissions, or you can use REVOKE to recycle permissions.
For example, if you want to revoke the delete permission of a user to a table:
REVOKE DELETE ON mydb.mytable FROM 'limited_user'@'%';
If you find that a user has too many permissions and want to reset the permissions, you can first REVOKE ALL and then reassign:
REVOKE ALL PRIVILEGES ON *.* FROM 'user_to_reset'@'%'; FLUSH PRIVILEGES;
Note: This does not delete the user itself, it just clears all permissions.
Delete users: Clean up accounts that are no longer needed in time
When a user no longer needs to access the database, it should be deleted in time to avoid leaving any security risks.
The command to delete a user is simple:
DROP USER 'old_user'@'localhost';
This operation will delete all permission records of the user at the same time. If you want to confirm whether the user exists, you can first check mysql.user table:
SELECT User, Host FROM mysql.user;
However, don't change this table directly. It is recommended to use commands such as CREATE USER , GRANT and DROP USER to manage users and permissions, which is safer and more standardized.
Basically that's it. Creation, authorization, adjustment, and deletion, the whole process looks quite intuitive, but in actual operation, you should pay special attention to the scope of permissions and the compatibility of password plug-in. As long as you follow the principle of minimum authority, most security risks can be controlled.
The above is the detailed content of Administering User Accounts and Privileges in MySQL. For more information, please follow other related articles on the PHP Chinese website!
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