expression.py 文件源码

python
阅读 20 收藏 0 点赞 0 评论 0

项目:pyetje 作者: rorlika 项目源码 文件源码
def exists(*args, **kwargs):
    """Return an ``EXISTS`` clause as applied to a :class:`.Select` object.

    Calling styles are of the following forms::

        # use on an existing select()
        s = select([table.c.col1]).where(table.c.col2==5)
        s = exists(s)

        # construct a select() at once
        exists(['*'], **select_arguments).where(criterion)

        # columns argument is optional, generates "EXISTS (SELECT *)"
        # by default.
        exists().where(table.c.col2==5)

    """
    return Exists(*args, **kwargs)
评论列表
文章目录


问题


面经


文章

微信
公众号

扫码关注公众号