DROP USER name
The message returned when a PostgreSQL user is successfully removed.
The error returned if the specified PostgreSQL user cannot be found on the connected host.
The error returned if a database called database still exists when you attempt to drop the name user. Any owned databases must first be removed.
Use the DROP USER command to remove a user from a database. You are not allowed to remove a user that owns a database. All database objects the user owned will continue to exist within the database.
Note: To run this command from the command prompt, use dropuser, which is a wrapper application to the same SQL command (see Chapter 10 for more about this command).
The following example permanently drops the PostgreSQL user named jonathan from the system:
template1=# DROP USER jonathan; DROP