CODEWITHSUNDEEP
python-3.xmongodbmongodb-queryaggregation-framework
Ajith Poojary
Ajith Poojary

Reputation: 3

MongoDb Aggregate Add Field with Multiple Condition Query Error

I am trying to execute this Mongodb query using python

pipeline = [{"$addFields": {"Status": {"$cond": [{"$and": [{"$gte": ["scores.0.score",40.0]},{"$gte": ["scores.1.score",40.0]},{"$gte": ["scores.2.score",40.0]}]},"Pass","Fail"]}}}]

Student_Status = list(db.Student_Collection.aggregate(pipeline))

enter image description here

what i am trying to do is to create a new field called "STATUS" where the student who scored more than 40 marks in all 3 categories their status will be updated to "Pass", Rest of the students their status will be updated to "Fail"

But in this code the All Student "Status" Field is updating to "Pass", Student who failed in 1 category their status is not updating to "Fail"

Upvotes: 0

Views: 124

Answers (1)

rickhg12hs
rickhg12hs

Reputation: 11932

Here's one way you could do it and "future proof" the pass criteria in case different "type"s have individual passing scores.

db.collection.aggregate([
  {
    "$set": {
      "allPass": {
        "$reduce": {
          "input": "$scores",
          "initialValue": true,
          "in": {
            "$switch": {
              "branches": [
                {
                  "case": {"$eq": ["$$this.type", "exam"]},
                  "then": {"$and": ["$$value", {"$gte": ["$$this.score", 40.0]}]}
                },
                {
                  "case": {"$eq": ["$$this.type", "quiz"]},
                  "then": {"$and": ["$$value", {"$gte": ["$$this.score", 40.0]}]}
                },
                {
                  "case": {"$eq": ["$$this.type", "homework"]},
                  "then": {"$and": ["$$value", {"$gte": ["$$this.score", 40.0]}]}
                }
              ]
            }
          }
        }
      }
    }
  },
  {
    "$set": {
      "Status": {"$cond": ["$allPass", "Pass","Fail"]},
      "allPass": "$$REMOVE"
    }
  }
])

Try it on mongoplayground.net.

Upvotes: 0

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