``io.sql.engine`` is used. The default ``io.sql.engine``
        behavior is 'sqlalchemy'

        .. versionadded:: 1.3.0

    **engine_kwargs
        Any additional kwargs are passed to the engine.

    Returns
    -------
    None or int
        Number of rows affected by to_sql. None is returned if the callable
        passed into ``method`` does not return an integer number of rows.

        .. versionadded:: 1.4.0

    Notes
    -----
    The returned rows affected is the sum of the ``rowcount`` attribute of ``sqlite3.Cursor``
    or SQLAlchemy connectable. The returned value may not reflect the exact number of written
    rows as stipulated in the
    `sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or
    `SQLAlchemy <https://docs.sqlalchemy.org/en/14/core/connections.html#sqlalchemy.engine.BaseCursorResult.rowcount>`__
    )