CODEWITHSUNDEEP
javascriptnode.jsmongodbmongodb-query
Anders Östman
Anders Östman

Reputation: 3832

Push more than one array in one Mongoskin query

Im using Mongodb with Mongoskin. I have the following data structure:

clients: {
  firstArray: [
    {
      _id: '153'.
      someField1: 'someVal1',
      someField2: 'someVal2'
    }
    ...
  ]

  secondArray: [
    {
      _id: '7423'.
      someField1: 'someVal1',
      someField2: 'someVal2',
      firstArrayIds: ['153, 154, 155, ...']
    }
    ...
  ]
}

Is it somehow possible to $push a object to firstArray, and in the same query add the _id to secondArray.firstArraysIds¨?

Upvotes: 0

Views: 259

Answers (1)

Neil Lunn
Neil Lunn

Reputation: 151132

Who said you can't do this? It''s pretty simple as $push is a "top level" update modifier, and as such takes a "document level" argument case:

db.collection.update(
    { "_id": someDocumentId, "secondArray._id": 7423 },
    {
       "$push": {
           "firstArray": someNewObject,
           "secondArray.$.firstArrayIds": someNewObject._id
       }
    }
);

So the positional $ operator allows you to update the element of "secondArray" that matched your condition.

The only thing you cannot do is match the elements of more than one array element in the document and ask for those "positions" to be updated. As the documentation says, only the first match index will be stored for the positional operator.

But in what you are asking to do, which requires a single match only then this is fine.

Upvotes: 3

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