MongoDB - 涉及列表的更新插入 [英] MongoDB - upsert involving lists

问题描述

我是一个 MongoDB 新手，想问一下如何编写一个涉及 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"}]
    }
]}

注意:

• 您提供行程名称和当前位置
• 如果行程尚不存在，则需要创建
• trips.name 应该是唯一的，这样如果存在，则附加到位置数组

这是我结合位置运算符和 $push 编写的查询.

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" } 
}

你可以看到

• trips"不是数组
• 它从字面上理解了$"并创建了一个用那个键(doh！)

到目前为止，我对 MongoDB 非常满意，但是编写复杂的查询肯定有一条陡峭的学习曲线.

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

我们将不胜感激任何反馈.

Any feedback will be appreciated.

提前致谢，艾米

推荐答案

你不能混合使用位置操作符 ("$") 和 upsert；在插入过程中，$"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.

我建议的结构更像这样:

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"}]
    }
}

然后你可以像这样发布更新:

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);

导致这个被插入.

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

再次运行它会给你这个:

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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