Create a Primary Key constraint on a specific column when the table is already created.

def set_primary_key(self, table, column):
        """Create a Primary Key constraint on a specific column when the table is already created."""
        self.execute('ALTER TABLE {0} ADD PRIMARY KEY ({1})'.format(wrap(table), column))
        self._printer('\tAdded primary key to {0} on column {1}'.format(wrap(table), column))