Question

在我的Mlab mongo 3.2数据库中，我有一个如下所示的集合：

{
"_id": {
    "$oid": "5752d....87985"
},
"name": "...etation",
"description": null,
"user_id": ".....",
"questions": [
    {
        "prompt": "The conclusions drawn seemed clear to most researchers, however, others were unconvinced, arguing that everything is open to ____________.",
        "answer": "interpretation",
        "created_at": "2014-11-09T14:59:38.154",
        "updated_at": "2014-11-09T14:59:38.154",
        "filled_answer": null
    },
    {
        "id": 922,
        "prompt": "His existential quest for Truth is in fact the key to his understanding and ____________ of the Bhagavad-Gītā.",
        "answer": "interpretation",
        "created_at": "2014-10-03T08:07:40.295",
        "updated_at": "2014-10-03T08:07:40.295",
        "filled_answer": null
    },
}

我正在努力解决的问题子文档存在两个问题：

有时但并非总是存在遗留的“id”字段，我想要取消设置但我的查询无效。
我想添加一个尚未存在的_id ObjectID字段。目前有些人有，有些人没有。

我尝试了很多查询，但似乎都没有。例如：

db.droplets.updateMany({"questions.$._id": { $exists: false }},{ $set: {"questions.$._id": new ObjectId()}},{"multi": true, "upsert": true})

Mongo告诉我“位置操作员没有找到查询所需的匹配”

更新

我已成功找到使用以下脚本删除所有问题的方法：

db.droplets4.find().forEach(function (doc) { 
  doc.questions.forEach(function (question) { 
    if (question.id) {
      delete question.id
    }
  });
  db.droplets.save(doc);
});

但是同样的策略不适用于添加对象ID。此代码不起作用：

db.droplets4.find().forEach(function (doc) { 
  doc.questions.forEach(function (question) { 
    if (!question._id) { question._id = new ObjectId() }
  });
  db.droplets.save(doc);
});

Answer 1

这应该适合你

db.droplets4.updateMany( { 
        "questions._id" : null
    },{ $set: {"questions.$._id": new ObjectId()}},{"multi": true, "upsert": true})

无法在Mlab中的mongo子文档中添加_id字段

1 个答案: