I have one collection that the structure of the record look like this,

{
  _id: ObjectId('66a544dc3a8dff9aaaf65343'),
  user_type: "USER",
  status: CREATE
}

The explanation of each field:

• _id : ID generate by MongoDB
• user_type : the record’s user type . Can only be USER, ADMIN, DEV
• status : the status. Can only be CREATE, ACTIVE, DELETE

I want to run the aggregate to get this output

{
  {
    _id: "ALL",
    stat: {
      "CREATE" : 2,
      "ACTIVE" : 5,
      "DELETE" : 4
    }
    "total": 11
  {
    _id: "USER",
    stat: {
      "CREATE" : 1,
      "ACTIVE" : 2,
      "DELETE" : 0
    },
    "total": 3
  },
  {
    _id: "ADMIN",
    stat: {
      "CREATE" : 0,
      "ACTIVE" : 3,
      "DELETE" : 0
    },
    "total": 3
  },
  {
    _id: "DEV",
    stat: {
      "CREATE" : 1,
      "ACTIVE" : 0,
      "DELETE" : 4
    },
    "total": 5
  }
}

I want to count each occurrence of status for all user_type, compute total number of all status, and create a TOTAL document to count the entire collection

I can easily generate all documents except _id: “ALL” document easily using $group with $project. The aggregate command look like this,

db.getCollection('accounts').aggregate(
  [
    {
      $group: {
        _id: '$user_type',
        CREATE: {
          $sum: {
            $cond: [
              {
                $eq: ['$$ROOT.status', 'CREATE']
              },
              1,
              0
            ]
          }
        },
        ACTIVE: {
          $sum: {
            $cond: [
              {
                $eq: ['$$ROOT.status', 'ACTIVE']
              },
              1,
              0
            ]
          }
        },
        DELETE: {
          $sum: {
            $cond: [
              {
                $eq: ['$$ROOT.status', 'DELETE']
              },
              1,
              0
            ]
          }
        },
      }
    },
    {
      $project: {
        stat: {
          CREATE: '$CREATE',
          ACTIVE: '$ACTIVE',
          DELETE: '$DELETE',
        },
        total: {
          $sum: [
            '$CREATE',
            '$ACTIVE',
            '$DELETE',
          ]
        }
      }
    }
  ],
); 

The problem arise when I want to generate another document. I can put another $group command (using _id: null), but it will delete all others record (the only thing left will be the record which _id: null) 

Is there a way to preserve the previous records in pipeline? or is there an alternative solution which is better that this? any comment is welcome.

Thank you very much!