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

Whatever you want to do involves a complex query. See the below query. Let me explain it first.

1- first pipeline $group is obvious to you.

2- second pipeline $lookup is required to generate your desired result as you want that the current prices and the already summarized prices should be compiled into one document.

3- third stage is just unwinding the array summary we have looked up so that we will be able to compile the prices.

4- fourth $project stage is doing what you really want to do that is to say that it is compiling the summary document you will be able to understand it.

5- generating the summary collection.

db.getCollection('userpricing').aggregate([
     {$group:{
            _id:"$user_id",
            Totalpositiveprice:{$sum:{$cond:{if:{ $gt:["$price",0]}, then: "$price", else: 0}}},
            Totalnegativeprice:{$sum:{$cond:{if:{ $lt:["$price",0]}, then: "$price", else: 0}}},
            Balanceprice:{"$sum":"$price"}
     }},
     {
      $lookup:
        {
          from: "summary",
          localField: "_id",
          foreignField: "user_id",
          as: "summary"
        }
     },
     {$unwind:{path:"$summary", preserveNullAndEmptyArrays:true}},
     {$project:{
         _id:0,
         user_id:"$_id",
         Balanceprice:{$add:["$Balanceprice", {$cond:{if:{ $eq:["$summary",undefined]}, then: 0, else: "$summary.Balanceprice"}}]},
         Totalnegativeprice:{$add:["$Totalnegativeprice", {$cond:{if:{ $eq:["$summary",undefined]}, then: 0, else: "$summary.Totalnegativeprice"}}]},
         Totalpositiveprice:{$add:["$Totalpositiveprice", {$cond:{if:{ $eq:["$summary",undefined]}, then: 0, else: "$summary.Totalpositiveprice"}}]}
     }},
   {$out:"summary"}  
])