MongoDb如何将文档的id更改为不同的

Question

您好，当某些ID相等时，如何将文档ID更改为Diffent？ 我想将一些员工更改为id_director到对象ID等于id_director。我的意思是，例如，当某些文档具有id_director = 100时，然后将其更改为_id，其中id_employeee = 100。

我当时尝试过这样的尝试：

var employes = db.employees.find({"id_director": {$ne: null}});
while (employes.hasNext()) {
emp = employes.next();
employe = db.employees.findOne({"id_director":emp.id_employe});


emp.id_director = employe._id

db.employees.save(emp)

}

例如，

我在一个集合中有两个文档：

employees
{
    "_id" : ObjectId("6224a5767b9cdbdcb681b1ef"),
    "id_employe" : 180,
    "id_director" : 100,
    "name" : "Mark"
}

{
    "_id" : ObjectId("6224a5767b9cdbdcb681b1f0"),
    "id_employe" : 100,
    "id_director" : null,
     "name" : "Peter"
}

预期文档：

{
    "_id" : ObjectId("6224a5767b9cdbdcb681b1ef"),
    "id_employe" : 180,
    "id_director" : ObjectId("6224a5767b9cdbdcb681b1f0"),
    "name" : "Mark"
}

Answer 1

首先你需要有 Peter 的 id 然后更新标记文档：

var peter= db.employees.findOne({_id: peterId});
db.employees.updateOne({
    _id: markId
}, {
    $set: {
        id_director: peter._id
    }
})

Answer 2

您可以执行一个自我$查找以查找导演，然后执行一些争吵，$ MERGE返回集合。

db.collection.aggregate([
  {
    "$match": {
      "id_director": {
        $ne: null
      }
    }
  },
  {
    "$lookup": {
      "from": "collection",
      "localField": "id_director",
      "foreignField": "id_employe",
      pipeline: [
        {
          "$limit": 1
        },
        {
          $project: {
            _id: 1
          }
        }
      ],
      "as": "id_director"
    }
  },
  {
    $unwind: "$id_director"
  },
  {
    $project: {
      _id: 1,
      id_employe: 1,
      id_director: "$id_director._id",
      name: 1
    }
  },
  {
    "$merge": {
      "into": "collection",
      "on": "_id",
      "whenMatched": "replace"
    }
  }
])

这是 mongo playground 供您参考。