How can i calculate price positive and negative price using mongodb or robomongo?

Question

below is my userpricing collection data

{
    \"_id\" : ObjectId(\"584bc9ba420a6b189c510af6\"),
    \"user_id\" : 1,
    \"mobilenumber\":\"01234\",
    \"p         


        

Answer 1

As from other answers, the problem with $out is that it will replace the summary collection if one exists and you may not want that. You can use a little JavaScript for that.

var cursor = db.userpricing.aggregate([
  {
    $group : {
      _id : "$user_id",
      Totalpositiveprice : {
        $sum : {
          $cond : {
            if: { $gte : ["$price" , 0]},
            then : "$price",
            else : 0
          }
        }
      },
      Totalnegativeprice : {
        $sum : {
          $cond : {
            if: {$lte : ["$price" , 0]},
            then : "$price",
            else : 0
          }
        }
      },
      Balanceprice : {$sum : "$price"}
    }
  },
  {
    $project : {
      _id : 0,
      user_id : "$_id",
      Totalpositiveprice : 1,
      Totalnegativeprice : 1,
      Balanceprice : 1
    }
  }
]);

while(cursor.hasNext()) {
  var elem = cursor.next();
  db.summary.update(
    {user_id : elem.user_id},
    elem,
    {upsert : true}
  );
}



> db.summary.find()
{ "_id" : ObjectId("58564bb71e2cb47f2ddcf1b4"), "Totalpositiveprice" : 10000, "Totalnegativeprice" : 0, "Balanceprice" : 10000, "user_id" : 2 }
{ "_id" : ObjectId("58564bb71e2cb47f2ddcf1b5"), "Totalpositiveprice" : 20000, "Totalnegativeprice" : -10000, "Balanceprice" : 10000, "user_id" : 1 }