CODEWITHSUNDEEP
mongodbpymongo
user94628
user94628

Reputation: 3721

Deleting specific record from an array nested within another array

I have a MongoDB record as follow:

"id": 1,
"Tasks": [
    {
        "description": "BLAH",
        "Tags": [
            {
                "Name": "test",
                "tagID": "YRG+crq3SJucvlUwTo/uSg=="
            },
            {
                "Name": "Cars",
                "tagID": "ObwiiZpNTOGECgHb1HehHg=="
            }
        ]

    },
    ......
  ]

I'm trying to delete the object from 'Tags' with the 'Name: test' by reference to its 'tagID'. The query I have deletes the whole record within 'Tasks' not just that particular Tags object.

db.user.update({ 'id': 1 }, 
    { 
        '$pull': { 'Tasks': {'Tags.tagID': "YRG+crq3SJucvlUwTo/uSg==" }}
    },
    { '$multi': 'true' }
)

How can I ammend my query to only remove that particular tag and not remove the entire record?

Upvotes: 2

Views: 74

Answers (3)

Sede
Sede

Reputation: 61225

Using Pymongo and the $ operator

col.update({"id": 1, "Tasks.description": "BLAH"},
    {
           "$pull": {"Tasks.$.Tags" : { "tagID": "YRG+crq3SJucvlUwTo/uSg==" }}
    }, multi=True 
)

Upvotes: 1

chridam
chridam

Reputation: 103335

Use the positional operator $ together with the $pull update operator to remove the specific array element object:

db.user.update({"id": 1, "Tasks.description": "BLAH"},
   {
       "$pull": {"Tasks.$.Tags" : { "tagID": "YRG+crq3SJucvlUwTo/uSg==" }}
   },
   { multi: true}
);

Upvotes: 1

Miguel A. Arilla
Miguel A. Arilla

Reputation: 5336

I think you are looking for the $unset command. Reference here.

Upvotes: 0

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