How to use element match inside condition statement of mongodb?

Question

I have two orders

Order A:

{
    "_id": "5e0092e725473011f4b4da54",
    "cash": 400.0,
    "deliveryFee": 5.0,
    "paymentOnPickUp" : false,
    "project": {
        "_id": "5dd3b4737908cb0cf7b40f84",
        "name": "Default Instant Deliveries"
    },
    "tasks": [{
            "tripType": "PICKUP",
            "status": "UNASSIGNED"
        },
        {
            "tripType": "DELIVERY",
            "status": "UNASSIGNED"
        }
    ]
}

Order B:

{
    "_id": "5e0092e725473011f4b4da54",
    "cash": 250.0,
    "deliveryFee": 15.0,
    "paymentOnPickUp" : true,
    "project": {
        "_id": "5dd3b4737908cb0cf7b40f84",
        "name": "Default Instant Deliveries"
    },
    "tasks": [{
            "tripType": "PICKUP",
            "status": "FAILED"
        },
        {
            "tripType": "DELIVERY",
            "status": "UNASSIGNED"
        }
    ]
}

Now i have to get aggregated information based on project. But i only need to add cash if task on pickUp is not failed.

Order A has cash collection of 400 and order B has collection of 800 order B has a pick up task which is failed. So we don't need to add cash but delivery fee should be added.

| Project                    | Cash | Delivery Fee | total Orders |
|----------------------------|------|--------------|--------------|
| Default Instant Deliveries | 400  | 20           | 2            |

Now following things which i tried is

fun getProjectsSummary(): MutableList<OrderSummaryDto> {

        val collectionPriceCondition = ConditionalOperators.`when`(where("tasks")
                .elemMatch(where("status").`is`("FAILED"))).then(0.0).otherwiseValueOf("cash")


        val agg = Aggregation.newAggregation(
                Aggregation.project()
                        .and("cashCollection").applyCondition(collectionPriceCondition),
                Aggregation.group("project.id")
                        .sum("deliveryFee").`as`("totalDeliveryPrice")
                        .sum("cashCollection").`as`("totalCashCollection")
                        .first("project.name").`as`("projectName")
                        .count().`as`("totalOrders")
        )
        return mongoTemplate
                .aggregate(agg, "ordersCollection", OrderSummaryDto::class.java).mappedResults
    }

But i am inside condition i am unable to use elematch.

Can anyone explain me how we can achieve this????

@MaheshBhatnagar we cannot do this. We are not going to change our structure. — Muhammad Waqas, Dec 26 '19 at 10:42
@MaheshBhatnagar What are actually you thinking? Can you explain please, may be i can do it — Muhammad Waqas, Dec 26 '19 at 10:56
@MaheshBhatnagar No bro we can't use this approach , we already have status field for different purpose — Muhammad Waqas, Dec 26 '19 at 13:12
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/204886/discussion-between-mahesh-bhatnagar-and-muhammad-waqas). — Mahesh Bhatnagar, Dec 26 '19 at 13:43

score 2 · Accepted Answer · answered Dec 30 '19 at 18:09

2

$elemMatch is only applicable in match stage. For any other stages you have to use ArrayOperators. You can use $in array operator.

Converting your condition to use in operator (using java code)

AggregationExpression collectionPriceCondition = ConditionalOperators.
                      when(ArrayOperators.arrayOf("tasks.status").containsValue("FAILED")).
                      then(0.0).
                      otherwiseValueOf("cash");

answered Dec 30 '19 at 18:09

s7vr

73,656
11
106
127

Let me check , finding this answer valuable for me. I didn't tried this yet. – Muhammad Waqas Jan 01 '20 at 05:39

Ashish Bakwad · Answer 2 · 2019-12-30T07:26:02.537

1

Have you tried this...

List<Criteria> criteriaList = new ArrayList<>();
criteriaList.add(where("tasks.status").`is`("FAILED"));
criteriaList.add(where("tasks.status").`nin`("COMPLETED"));
val collectionPriceCondition = ConditionalOperators.`when`(new Criteria().andOperator(criteriaList.toArray(new Criteria[criteriaList.size()])))).then(0.0).otherwiseValueOf("cash")

edited Dec 30 '19 at 07:26

answered Dec 30 '19 at 06:19

Ashish Bakwad

791
4
15

Yes bro i tried this. But if i have multiple failed task and one pickUp task is Completed it not gonna work. – Muhammad Waqas Dec 30 '19 at 06:49
Secondly i have to check taskType as well. e.g if paymentOnPickUp= true i have to check failed task of pickUp only else i have to check failed task of delivery. – Muhammad Waqas Dec 30 '19 at 06:50
let me check bro – Muhammad Waqas Dec 30 '19 at 07:36

How to use element match inside condition statement of mongodb?

2 Answers2