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Accepted
Shevtsov Eugene
Asked:2022-09-26 07:05:40 +0000 UTC2022-09-26 07:05:40 +0000 UTC

如何从 monga 中选择对评论的回复？

  • 772

如何在一个聚合的框架内获得评论的答案？例子：

{
 "_id": 1,
 "reply_for": null,
 "comment": "комментарий"
},
{
 "_id": 2,
 "reply_for" 1,
 "comment": "Ответ"
}

是否有可能在一个聚合的框架内做到这一点，例如，在你得到的输出

{
     "_id": 1,
     "reply_for": null,
     "comment": "комментарий",
     "reply" : [
        {
          "_id": 2,
         "reply_for": 1,
          "comment": "Ответ"
        },
     ]
    },
mongodb

1 个回答

  1. Best Answer
    ....
  ['$addFields' =>  ['comment_id' => ['$toString' => '$_id']],
  ['$lookup' => [
     'from' => 'collection',
     'localField' => 'comment_id',
     'foreignField' => 'reply_for',
     'as' => 'reply',
  ]
  ]
....
    • 0

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