I have a collection with documents, like this:

{
 _id: ObjectId('xyz'),
 companyId: 'xyz',
 lastModifiedByUserEmail: '[email protected]'
}

I need to know the lastModifiedByUserEmail with more occurrences, the quantity of occurrences, by companyId.

I know how to make the the count of occurrences by lastModifiedByUserEmail:

{ $group: { _id: '$lastModifiedByUserEmail', total: { $sum: 1 } } }

But I don't know how to group it by companyId.

CodePudding user response：

You can add a multi-part id to group on:

{
  $group: {
    _id: {
      "lastModifiedByUserEmail": "$lastModifiedByUserEmail",
      "company": "$companyId"
    },
    total: {
      $sum: 1
    }
  }
}

If you want to get the highest, then add in a sort and limit?

  {
    $sort: {
      total: -1
    }
  },
  {
    $limit: 1
  }

https://mongoplayground.net/p/vzfv8eUYHaz