sql - 为什么此 SQLAlchemy 查询返回未请求的不合逻辑值？

Question

    posts_query = (db.session.query(Post).
                   join(PostOption,PostOption.post_id == post_obj.id).
                   filter(and_(PostOption.key == "name",
                               PostOption.val == 'a')).
                   filter(Post.place_id == post_obj.place_id)
                   )

    print map(lambda x:get_post_values(x),posts_query.all())

返回

[{u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'a'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}, {u'name': u'b'}]

Answer 1

在这里疯狂猜测：

在 and_ 中包含 place_id 子句：

posts_query = (db.session.query(Post).
           join(PostOption,PostOption.post_id == post_obj.id).
           filter(and_(PostOption.key == "name",
                       PostOption.val == 'a',
                       Post.place_id == post_obj.place_id))
           )

Answer 2

认为这是连接，看来您正在将 Post 加入 PostOptions 上 PostOption.post_id = 一些文字值。认为你的意思是这样的：

posts_query = (db.session.query(Post).
  join(PostOption, PostOption.post_id == Post.id).
  filter(and_(PostOption.key == "name", PostOption.val == 'a')).
  filter(Post.place_id == post_obj.place_id).
  filter(Post.id == post_obj.id)
)