This MySQL error —
ERROR 1396 (HY000): Operation ALTER USER failed for 'Mysql'@'%'
— means that MySQL cannot find the user 'Mysql'@'%' to alter, or the user definition is inconsistent in the internal privilege tables.
Possible Causes-
1. User doesn’t exist.
The user 'Mysql'@'%' may not exist in the mysql.user table.
2. User exists but has corruption or a mismatch.
Sometimes the internal data becomes inconsistent, especially after an upgrade or manual edits.
3. Privileges issue.
The currently logged-in MySQL user doesn’t have enough privileges to modify other users.
4. MySQL version difference.
The command syntax differs slightly between MySQL 5.7, 8.0, and MariaDB.
Solution-
Check if user exists
Run this:
`sql SELECT User, Host FROM mysql.user WHERE User = 'Mysql';
` If you get no rows, the user doesn’t exist
— MySQL can’t “alter” a non-existent account.
If the user doesn’t exist,
create it first
`sql CREATE USER 'Mysql'@'%' IDENTIFIED BY 'yourpasswordhere';
` Then you can alter if needed:
`sql ALTER USER 'Mysql'@'%' IDENTIFIED BY 'newpasswordhere';
` If user exists but still fails Drop and recreate the account cleanly:
`sql DROP USER 'Mysql'@'%'; CREATE USER 'Mysql'@'%' IDENTIFIED BY 'yourpasswordhere'; ` >
Make sure you can safely drop the user —
This will remove all privileges assigned to it.
Grant privileges again (if needed)
`sql GRANT ALL PRIVILEGES ON . TO 'Mysql'@'%' WITH GRANT OPTION;
FLUSH PRIVILEGES; `
Note-
• Check your MySQL version using:
`sql SELECT VERSION(); `
• In MySQL 8.0,
password updates use:
`sql ALTER USER 'Mysql'@'%' IDENTIFIED WITH mysqlnativepassword BY 'new_password';
• Make sure you’re logged in as a user with UPDATE or ALTER USER privilege, such as root` or another admin.
