MongoDB-涉及列表的upsert

问题描述

我是MongoDB新手，想问一下如何编写涉及upsert和list的更新命令.

I'm a MongoDB newbie and wanted to ask how to write an update command involving upsert and list.

基本上我想完成这样的事情:

Basically I want to accomplish something like this:

{"_id" : ObjectId("4c28f62cbf8544c60506f11d"),
"some_other_data":"goes here",
"trips": [
    {"name": "2010-05-10",
     "loc": [{"lat":21.321231, "lng": 16.8783234, "updated_at": "Mon May 10 2010 15:24:35"},
        {"lat":21.321231, "lng": 16.8783234, "updated_at": "Mon May 10 2010 15:24:24"}]
    },
    {"name": "2010-05-08",
     "loc": [{"lat":21.324239, "lng": 16.8735234, "updated_at": "Mon May 8 2010 11:18:05"},
        {"lat":21.311234, "lng": 16.8743271, "updated_at": "Mon May 8 2010 11:17:55"},
        {"lat":21.321238, "lng": 16.8782219, "updated_at": "Mon May 8 2010 11:17:45"}]
    }
]}

请注意:

• 您提供旅行名称和当前位置
• 如果旅行尚不存在，则为需要创建
• trips.name应该是唯一的，以便如果存在，则将其附加到位置数组

• You supply a trip name and thecurrent location
• If the trip does not exist already, itneeds to be created
• trips.name should be unique so thatif it exists, you append to thelocation array

这是我写的结合$ push的位置运算符的查询.

This is the query I wrote combining the positional operator with $push.

    db.mycollection.update({"application_id": "MyTestApp",
                            "trips.name": "2010-05-10"},
                           {$push: {'trips.$.loc': {"lat":11, "lng":11} }},
                           true);

但这会导致这样的数据:

But this results in data like this:

> db.mycollection.find({"application_id":"MyTestApp"})
{ "_id" : ObjectId("4c29044ebf8544c60506f11f"),
"application_id" : "MyTestApp",
"trips" : { "$" : { "loc" : [ { "lat" : 11, "lng" : 11 } ] },
"name" : "2010-05-10" }
}

您可以看到

• 行程"不是数组
• 从字面上取了"$"并创建了一个键(那个！！)

• "trips" is not an array
• it took "$" literally and created akey with that (doh!)

到目前为止，我对MongoDB一直很满意，但是在编写复杂的查询时肯定有一个陡峭的学习曲线.

So far I've been pretty happy with MongoDB, but there's definitely a steep learning curve with writing complicated queries.

任何反馈将不胜感激.

Any feedback will be appreciated.

预先感谢，艾米

推荐答案

您不能混合使用位置运算符("$")和upsert；在插入过程中，"$"将被视为字段名称.您不能对新文档执行此操作，只能对现有文档执行此操作.

You can't mix the positional operator ("$") and an upsert; the "$" will be treated as a field name during the insert. You can't do this for new documents, only existing one.

我建议了一个更像这样的结构:

I suggested a structure more like this:

{"_id" : ObjectId("4c28f62cbf8544c60506f11d"),
"some_other_data":"goes here",
"trips": {
    "2010-05-10":
       [{"lat":21.321231, "lng": 16.8783234, "updated_at": "Mon May 10 2010 15:24:35"},
        {"lat":21.321231, "lng": 16.8783234, "updated_at": "Mon May 10 2010 15:24:24"}],
    "2010-05-08":
       [{"lat":21.324239, "lng": 16.8735234, "updated_at": "Mon May 8 2010 11:18:05"},
        {"lat":21.311234, "lng": 16.8743271, "updated_at": "Mon May 8 2010 11:17:55"},
        {"lat":21.321238, "lng": 16.8782219, "updated_at": "Mon May 8 2010 11:17:45"}]
    }
}

然后您可以发布如下更新:

Then you can issue an update like this:

db.mycollection.update({application_id: "MyTestApp", "trips.2010-05-10":{$exists:true}},
                       {$push: {"trips.2010-05-10": {lat:11, lng:11} }},
                       true);

将其插入.

> db.mycollection.find()
{ "_id" : ObjectId("4c2931d17b210000000045f0"),
    "application_id" : "MyTestApp",
    "trips" : { "2010-05-10" : [ { "lat" : 11, "lng" : 11 } ] } }

并再次运行它可以为您提供:

and running it again give you this:

> db.mycollection.find()
{ "_id" : ObjectId("4c2932db7b210000000045f2"),
    "application_id" : "MyTestApp",
    "trips" : { "2010-05-10" :
        [ { "lat" : 11, "lng" : 11 },
          { "lat" : 11, "lng" : 11 } ] } }

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