如何在MongoDB中将数据添加到（大量）嵌套集合中

Question

I am a noob at Python and MongoDB and would really appreciate your help with my problem. My collection in MongoDB looks like this:

{
 "Segments" : [
                {
                  Devices : [
                              "IP" : "",
                              "Interfaces" : 
                                             [
                                               {
                                                 "Name" :""
                                               }
                                             ],
                             ],
                             "DeviceName" : "",
                             "SegmentName" : ""
                 }
                ]
}

I have an object like so:

Node Details: {'node:98a': ['Sweden', 'Stockholm', '98a-3470'], 'node:98b': ['Denmark', 'Copenhagen', '98b-3471', '98b-3472']}

I need to update the 'Name' within 'Interfaces' part in the collection above, with values from the Node Details dictionary. I have tried using $set, $addToSet, $push etc., but nothing is helping. I have already added the Segment and DeviceName information.

The output should be as follows:

{
     "Segments" : [
                    {
                      Devices : [
                                  {
                                   "Interfaces" : 
                                                 [
                                                   {
                                                     "Name" :"98a-3470"
                                                   }
                                                 ],
                                   "DeviceName" : "node:98a",
                                  }
                                  {
                                   "Interfaces" : 
                                                 [
                                                   {
                                                     "Name" :"98b-3471"
                                                   },
                                                   {
                                                     "Name" :"98b-3472"
                                                   }
                                                 ],
                                   "DeviceName" : "node:98b",
                                  }
                                 ],                                 
                      "SegmentName" : "segmentA"
                     }
                    ]
    }

Any help would be greatly appreciated. I have tried a lot in the MongoDB shell and also on Google, but to no avail. Thank you all.

Regards, trupsster

[[ EDITED ]] Okay, here is what I have got so far after continuing to poke around after posing the question: I used the following query in MongoDB shell:

db.test.mycoll.update({'Segments.SegmentName':'segmentA','Segments.Devices.Name':'node:98a'}, {$set: {"Segments.$.Devices.0.Interfaces.Name" : "98b-3470"}})

Now this inserted in the correct place as per my 'schema', but when I try to add the second interface, it simply replaces the earlier one. I tried using $push (complained about it not being an array), and $addToSet (showed another error), but none helped. Can you please help me from this point on?

Thanks, trupsster

[[ Edited again ]]

I found the solution! Here is what I did: To add an interface to an existing device:

db.test.mycoll.update({'Segments.SegmentName':'segmentA','Segments.Devices.Name':'node:98a'}, {$addToSet: {"Segments.$.Devices.0.Interfaces.Name" : "98a-3471"}})

Now, to append to the dict with a new 'Name' within the array 'Interfaces':

db.test.mycoll.update({'Segments.SegmentName':'segmentA','Segments.Devices.Name':'node:98a'}, {$addToSet: {"Segments.$.Devices.0.Interfaces" : {"Name" : "98a-3472"}}})

As you can see, I used $addToSet.

Now, next step was to add the same information (with different values) to 2nd device, which was done like so:

db.test.mycoll.update({'Segments.SegmentName':'segmentA','Segments.Devices.Name':'node:98b'}, {$addToSet: {"Segments.$.Devices.1.Interfaces" : {"Name" : "98b-3473"}}})

So that was it! I am so chuffed with myself! Thank you all who took time to read my problem. I hope my solution will help someone.

Regards, trupsster

Answer 1

You did not say what you actually tried. To access a sub-document inside an array, you need to use dot notation with numeric indices. So to address the Name field in your example:

Segments.Devices.0.Interfaces.0.Name

Did you try that? Does it work?