def is_credential_valid(self, credential_id):
        """
        Check if this credential ID is valid.
        """
        q = select(self.UsersTable).filter(
            self.UsersTable.c.id == credential_id,
            self.UsersTable.c.password is not None,
        )
        results = self.conn.execute(q).all()
        return len(results) > 0

        Check if this credential ID is valid.
        
cme/protocols/mssql/database.py