def create_table(db, schema_name, table_name, columns):
    """
    Create a table, schema_name.table_name, in given database with given list of column names.
    """
    table = '{}.{}'.format(schema_name, table_name
        ) if schema_name else table_name
    db.execute('DROP TABLE IF EXISTS {}'.format(table))
    columns_list = ', '.join(columns)
    db.execute('CREATE TABLE {} ({})'.format(table, columns_list))
