Mongodb 从子集合中删除属性

我试图使用mongodb从其父集合（列表）的子集合（ListingFeatures）中删除属性（_id）。换句话说，我有一个Listing对象，其中有一个ListingFeature对象列表。ListingFeature有一个我正试图删除的_id属性

以下是我尝试过的命令，我认为它会起作用：

db.Listing.update( { "ListingFeatures._id": { $exists:true } }, { $unset: { "ListingFeatures._id": 1 } }, false, true);

在完成之前，它运行了约30分钟（列表有300万条记录），没有抛出任何错误或给出任何类型的消息说它成功或失败，但是Listing.ListingFeatures.\u id属性仍然存在

我错过了什么

这是一个精简的示例清单文档。最后，我想从ListingFeatures集合中删除_id、CreateDate和UpdateDate

{
  "Address": "1080 DUNLAP ORPHANAGE RD",
  "City": "Unincorporated",
  "ListingFeatures": [
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Status: ACTIVE"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "County: Tipton"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Approximately 10 acre(s)"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "2 total full bath(s)"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "2 total half bath(s)"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "9 total rooms"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "2 stories"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Type:  General Residential"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Master Bedroom is Carpet, Full Bath, Level 1, Walk-In Closet"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Basement is Partial, Unfinished"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Pool features:  Above Ground"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "2 covered parking space(s)"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Yes car garage(s)"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Attached parking"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Cooling features:  220 Wiring, Dual System,Cooling"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Inclusions:  Cooktop, Dishwasher, Gas Cooking, Microwave, Refrigerator, Satellite Dish, Self Cleaning Oven"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Lot features:  Chain Fenced, Landscaped, Level, Some Trees, Wooded"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Lot size is between 10 and 20 acres"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Utilities present:  Public Water, Septic Tank"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Swimming pool(s)"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Basement"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Den"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Laundry room"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Hardwood floors"
    },
    {
      "_id": null,
      "CreateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "UpdateDate": "Sun, 03 Apr 2011 19:40:04 GMT -04:00",
      "Name": "Parking features:  Driveway/Pad, Garage Door Opener(s), Storage Room(s), Workshop(s)"
    }
  ],
  "ZipCode": "38011",
  "_id": {
    "$oid": "4d99055b1b9ba917bcef9443"
  }
}

---

我很确定你不能删除

\u id

（事实上，你甚至不能删除上面的索引）。它是MongoDB保留的字段，用作文档标识符

编辑

好了，我得用这个

让我们删除此集合中someid为“456”的CreateDate

> db.stackoverflow.update({"ListingFeatures.someid":"456"},{$unset:{"ListingFeatures.$.CreateDate":1}});                                                    

现在我们验证CreateDate是否从someid为“456”的元素中消失

---

我很确定你不能删除

\u id

（事实上，你甚至不能删除上面的索引）。它是MongoDB保留的字段，用作文档标识符

编辑

好了，我得用这个

让我们删除此集合中someid为“456”的CreateDate

> db.stackoverflow.update({"ListingFeatures.someid":"456"},{$unset:{"ListingFeatures.$.CreateDate":1}});                                                    

现在我们验证CreateDate是否从someid为“456”的元素中消失

---

对我来说，只有一种工作方式。 即使在孩子里面也要和孩子一起工作

var updated_comment = 0;
db.Document.find().forEach(function(doc){

    function remove_errors(comments){
        comments.forEach(function(comment){
            delete comment.errors
            updated_comment = updated_comment + 1;
            remove_errors(comment.comments);
        });
    }

    remove_errors(doc.comments);

    db.Document.save(doc);
});

print("done updated_comment = " + updated_comment);

---

对我来说，只有一种工作方式。 即使在孩子里面也要和孩子一起工作

var updated_comment = 0;
db.Document.find().forEach(function(doc){

    function remove_errors(comments){
        comments.forEach(function(comment){
            delete comment.errors
            updated_comment = updated_comment + 1;
            remove_errors(comment.comments);
        });
    }

    remove_errors(doc.comments);

    db.Document.save(doc);
});

print("done updated_comment = " + updated_comment);

---

您是否也尝试了不带查询的更新

{“ListingFeatures.\u id:{$exists:true}

？这行吗？刚刚尝试过，并且_id属性仍然存在：db.Listing.update（{}，{$unset:{“ListingFeatures._id:1}，false，true）；您是否也尝试了不带查询的更新

{“ListingFeatures.\u id:{$exists:true}

？这行吗？刚刚尝试过，并且_id属性仍然存在：db.Listing.update（{}，{$unset:{“ListingFeatures._id:1}，false，true）；我已尝试从子集合中删除另一个属性以进行检查，但该属性也未被删除，因此它与_id无关。您能否粘贴此集合中的文档作为示例？@lobster1234-编辑原始问题以添加示例文档。如我所说，它对_id不起作用。下面是错误：>db.stackoverflow.update（{u id:new ObjectId（“4db5aa80a1f7a7b35c69b301”）}，{$unset:{u id:1}，true，true）；Mod on _id不允许正如我所说，我尝试为_id之外的其他属性（如CreateDate）执行此操作，但仍然不起作用。我尝试从子集合中删除另一个属性以进行检查，但该属性也未被删除，所以它与_id无关。你能粘贴这个集合中的文档作为例子吗？@lobster1234-编辑原始问题以添加示例文档。正如我所说，它对_id不起作用。下面是错误：>db.stackoverflow.update（{u id:new ObjectId（“4db5aa80a1f7a7b35c69b301”），{$unset:{u id:1}，true，true）；Mod on _id不允许正如我所说的，我尝试为除_id之外的另一个属性（如CreateDate）执行此操作，但仍然不起作用。