需要帮助mysql查询

Question

第一段背景信息：这是关于cms，它保存对象 - 对象关系及其在单个表中的排序，列是object_id，parent_id和排序顺序

第二件有多个连接的查询，我想按2个参数排序。其中一个是对象本身的排序，第二个是其父对象的排序顺序。

我现在的查询是：

SELECT obj_asset.*, object.headline AS title, oo.sort_order AS sort, op.sort_order FROM obj_asset 
JOIN object ON obj_asset.object_id = object.object_id 
JOIN object_object AS oo on obj_asset.object_id = oo.object_id
JOIN (SELECT sort_order from object_object WHERE object_id = (SELECT parent_id from object_object WHERE object_id = obj_asset.object_id )) AS op ON obj_asset.object_id = oo.object_id
WHERE obj_asset.profile_id = 140 AND obj_asset.rsvp_enabled = 1 AND object.is_published = 1 ORDER BY sort DESC;

它不起作用。这样可以正常工作：

SELECT obj_asset.*, object.headline AS title, oo.sort_order AS sort, op.sort_order FROM obj_asset 
JOIN object ON obj_asset.object_id = object.object_id 
JOIN object_object AS oo on obj_asset.object_id = oo.object_id
JOIN (SELECT sort_order from object_object WHERE object_id = (SELECT parent_id from object_object WHERE object_id = 11111 )) AS op ON obj_asset.object_id = oo.object_id
WHERE obj_asset.profile_id = 140 AND obj_asset.rsvp_enabled = 1 AND object.is_published = 1 ORDER BY sort DESC;

我得到的错误是：

1054 - 'where子句'中的未知列'obj_asset.object_id'

我怎样才能让它发挥作用？

谢谢！

编辑：我可以解决这个问题，如果我可以提出替代方法来包括父母排序查询。有这样的方式吗？

Answer 1

正如您已经想到的那样，问题是您尝试在子查询的约束中使用外部查询中的列：

  (SELECT sort_order
      from object_object
      WHERE object_id = (SELECT parent_id
                         from object_object
                         WHERE object_id = obj_asset.object_id )
     )

可以重写此子查询，但仅查看原始查询时不清楚。

原始查询（重新格式化）可能存在错误：

SELECT obj_asset.*, object.headline AS title, oo.sort_order AS sort, op.sort_order
FROM obj_asset 
JOIN object ON obj_asset.object_id = object.object_id 
JOIN object_object AS oo on obj_asset.object_id = oo.object_id
JOIN (SELECT sort_order
      from object_object
      WHERE object_id = (SELECT parent_id
                         from object_object
                         WHERE object_id = obj_asset.object_id )
     ) AS op ON obj_asset.object_id = oo.object_id
WHERE obj_asset.profile_id = 140 AND obj_asset.rsvp_enabled = 1 AND object.is_published = 1 ORDER BY sort DESC;

名为op的子查询未在任何join或where子句中使用。

我的最佳猜测是您想要的以下内容：

SELECT obj_asset.*, object.headline AS title, oo.sort_order AS sort, op.sort_order
FROM obj_asset 
JOIN object ON obj_asset.object_id = object.object_id 
JOIN object_object AS oo on obj_asset.object_id = oo.object_id
JOIN (SELECT sort_order, o2.object_id
    from object_object as o1
    INNER JOIN object_object as o2 ON o1.object_id = o2.parent_id
    ) AS op ON obj_asset.object_id = op.object_id
WHERE obj_asset.profile_id = 140 AND obj_asset.rsvp_enabled = 1 AND object.is_published = 1 ORDER BY sort DESC;

Answer 2

您的子查询在FROM子句中不包含obj_asset。

(SELECT parent_id FROM object_object WHERE object_id = obj_asset.object_id )

让这部分运行起来，你应该有更好的运气。

只是一个提示......如果你在SQL语句中添加更多的换行符和缩进词，你就会更容易发现问题。

Answer 3

我认为您需要输入此内容（包括obj_asset到FROM）：

(SELECT parent_id FROM object_object, obj_asset  WHERE object_object.object_id = obj_asset.object_id )

但不是这样：

(SELECT parent_id from object_object WHERE object_id = obj_asset.object_id )