How to add and change SQL passwords?

You can add or change a password for an existing account with the SET PASSWORD query, as follows:

SET PASSWORD FOR username@hostname = PASSWORD(‘password’)

The account is set to password for the account username@hostname. If the account currently has a password, the password is changed. You do not need to specify the FOR clause. If you do not, the password is set for the account you are currently using.
You can remove a password by sending the SET PASSWORD query with an empty password, as follows:

SET PASSWORD FOR username@hostname = PASSWORD(‘’)