expression.py 文件源码

def union_all(*selects, **kwargs):
    """Return a ``UNION ALL`` of multiple selectables.

    The returned object is an instance of
    :class:`.CompoundSelect`.

    A similar :func:`union_all()` method is available on all
    :class:`.FromClause` subclasses.

    \*selects
      a list of :class:`.Select` instances.

    \**kwargs
      available keyword arguments are the same as those of
      :func:`select`.

    """
    return CompoundSelect(CompoundSelect.UNION_ALL, *selects, **kwargs)