MongoDB fails to update nested array in java

Question

I have a following JSON object in database,

{
    "_id": "FlightLegPaxRecord::UA::141::2019-09-07::ORD::DEN",
    "activeInd": "0",
    "additionalProperties": {},
    "arrivalAirport": "DEN",
    "carrierCode": "UA",
    "departureAirport": "ORD",
    "departureDate": "2019-09-07",
    "docType": "FlightLegPaxRecord",
    "flightNumber": "141",
    "fltLclOrigDt": "2019-09-07",

    "travelerCounts": [{
        "additionalProperties": {},
        "counts": [{
            "additionalProperties": {},
            "key": "J",
            "value": "7"
        }, {
            "additionalProperties": {},
            "key": "Y",
            "value": "0"
        }],
        "travelCountType": "ActionStatus"
    }, {
        "additionalProperties": {},
        "counts": [{
            "additionalProperties": {},
            "key": "J",
            "value": "44"
        }, {
            "additionalProperties": {},
            "key": "Y",
            "value": "274"
        }],
        "travelCountType": "ActualCapacity"
    }]
}

Following is my java code to update the value field of the count array which matches a travelCountType.

Following is my java code:

Map<String, String> queryMap = new HashMap<>();
queryMap.put("_id", "FlightLegPaxRecord::UA::141::2019-09-07::ORD::DEN");
queryMap.put("travelerCounts.travelCountType", "ActionStatus");
queryMap.put("travelerCounts.counts.key", "J");

Map<String, String> updQuery = new HashMap<>();
updQuery.put("travelerCounts.counts.$.value", "99");

Document query = constructDocument(queryMap);
Document setData = constructDocument(updQuery);
Document update = new Document();
update.append("$set", setData);
MongoCollection collection = database.getCollection(colName);
UpdateResult result = collection.updateOne(query, update);

private Document constructDocument(Map<String, String> searchQuery) {
Iterator<Map.Entry<String, String>> searchIterator = searchQuery.entrySet().iterator();
Document query = new Document();

while (searchIterator.hasNext()) {
    Map.Entry<String, String> entry = searchIterator.next();
    query.append(entry.getKey(), entry.getValue());
}

return query;
}

After executing the code, i am getting the following exception

Caused by: com.mongodb.MongoWriteException: Cannot create field 'counts' in element {travelerCounts: [ { additionalProperties: {}, counts: [ { additionalProperties: {}, key: "J", value: "7" }, { additionalProperties: {}, key: "Y", value: "0" } ], travelCountType: "ActionStatus" }, { additionalProperties: {}, counts: [ { additionalProperties: {}, key: "J", value: "44" }, { additionalProperties: {}, key: "Y", value: "274" } ], travelCountType: "ActualCapacity" } ]}
    at com.mongodb.client.internal.MongoCollectionImpl.executeSingleWriteRequest(MongoCollectionImpl.java:967)
    at com.mongodb.client.internal.MongoCollectionImpl.executeUpdate(MongoCollectionImpl.java:951)
    at com.mongodb.client.internal.MongoCollectionImpl.updateOne(MongoCollectionImpl.java:613)
    at com.mongodb.client.internal.MongoCollectionImpl.updateOne(MongoCollectionImpl.java:608)
    at com.ual.noc.connector.service.MongoCrudServiceImpl.updateSingleDocument(MongoCrudServiceImpl.java:90)
    at com.ual.noc.connector.TestMongo.testUpdate(TestMongo.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136)
    ... 17 more

I am not able to understand where i am going wrong. Please help me in resolving the issue. Thanks in advance. Please let me know if i need to elaborate the issue in more detail.

It's because you're updating a value inside an array, This document has complex structure since it has to filter on array inside an array maybe it would not be normal update using positional operators, What is your mongoDB version ? — whoami - fakeFaceTrueSoul
– whoami - fakeFaceTrueSoul, Commented Jan 6, 2020 at 23:49
mongoDB Version: 4.2.1. I was following this concept for the update. — Pallab
– Pallab, Commented Jan 7, 2020 at 1:29
@palab : not sure how it's working in that link, but in general that error is right as you're trying to update one object in travelerCounts array without any positional operator — whoami - fakeFaceTrueSoul
– whoami - fakeFaceTrueSoul, Commented Jan 7, 2020 at 3:25
Can you tell what is the Java driver you are using? Also, did you try the update code in the mongo shell before converting it to Java? — prasad_
– prasad_, Commented Jan 7, 2020 at 8:44
What would the output (or result) document look like after the update? — prasad_
– prasad_, Commented Jan 7, 2020 at 8:57

prasad_ · Accepted Answer · 2020-01-07 09:26:45Z

1

The solution is to use the update filtered positional operator.

The Java Code:

Bson queryFilter = eq( "_id", "FlightLegPaxRecord::UA::141::2019-09-07::ORD::DEN" );

List<Bson> arrayFilters = new ArrayList<>();
arrayFilters.add(new Document( "tc.travelCountType", "ActionStatus" )); // "tc" for "travelerCounts"
arrayFilters.add(new Document( "ct.key", "J" )); // "ct" for "travelerCounts.counts"
UpdateOptions updateOptions = new UpdateOptions().arrayFilters(arrayFilters);

Bson update = set( "travelerCounts.$[tc].counts.$[ct].value", "99" );

UpdateResult result = collection.updateOne(queryFilter, update, updateOptions);

[Edit ADD]

The code updQuery.put("travelerCounts.counts.$.value", "99") will produce errors or an incorrect result. According to MongoDB documentation on $ and Nested Arrays

The positional $ operator cannot be used for queries which traverse more than one array....

The update in the query is a nested array with two levels. So, the solutions can be one of these:

The one I have already provided (above).
You can also use aggregation with the update method. The MongoDB version 4.2 has feature that allows using Aggregation pipeline instead of an update.
If you are using MongoDB versions 4.0 or earlier, you can use an aggregation and then an update on the aggregation result.

edited Jan 7, 2020 at 9:26

answered Jan 7, 2020 at 3:36

prasad_

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1 Comment

Pallab Over a year ago

Thanks for the help. The code you provided works just fine!

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