java - MongoDB 无法更新 java 中的嵌套数组

Question

我在数据库中有一个以下 JSON 对象，

{
    "_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"
    }]
}

以下是我的 java 代码，用于更新与 travelCountType 匹配的 count 数组的 value 字段。

以下是我的java代码:

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;
}

执行代码后，出现以下异常

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

我不明白我哪里出了问题。请帮助我解决问题。提前致谢。如果我需要更详细地阐述该问题，请告诉我。

Answer 1

解决方案是使用 update filtered positional operator .

Java 代码:

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);

<小时/>[ 编辑添加]

代码 updQuery.put("travelerCounts.counts.$.value", "99") 将产生错误或不正确的结果。根据 MongoDB 文档 $ and Nested Arrays

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

查询中的更新是一个两层嵌套数组。因此，解决方案可以是以下之一:

1. 我已经提供了(上面)。
2. 您还可以使用聚合 update方法。 MongoDB 版本 4.2 具有允许使用的功能聚合管道而不是更新。
3. 如果您使用的是 MongoDB 4.0 或更早版本，则可以使用聚合，然后更新聚合结果。