查询与mongodb中的条件匹配的文档及其所有子文档(使用spring) [英] Query a document and all of its subdocuments that match a condition in mongodb (using spring)

问题描述

我有一个MongoDB，用于存储来自不同传感器的数据.它具有以下结构:

I have a MongoDB storing data from different sensors. It has the following structure:

 {
     "_id" : 1,
     "sensorName" : "Heart Rate",
     "samplePeriod" : 1000,
     "data" : [
             {
                 "timestamp" : NumberLong("1483537204046"),
                 "dataPoints" : [ 68 70 ]
             },
             {
                 "timestamp" : NumberLong("1483537206046"),
                 "dataPoints" : [ 68 70 ]
             }
     ]
}
{
    "_id" : 2,
    "sensorName" : "Ambient Light",
    "samplePeriod" : 500,
    "data" : [
            {
                "timestamp" : NumberLong("1483537204058"),
                "dataPoints" : [ 56, 54, 54, 54 ]
            },
            {
                "timestamp" : NumberLong("1483537206058"),
                "dataPoints" : [ 56, 54, 54, 54 ]
            }
    ]
}

例如，现在我需要心率"-包含所有字段和数据"字段的文档-匹配条件"1483537204000和1483537214000之间的时间戳记"的子文档.

Now for example i need the "Heart Rate" - document with all of its fields and those of its "data" - subdocuments matching the condition "timestamp between 1483537204000 and 1483537214000".

我已经在另一个问题的mongo shell中获得了有关如何执行此操作的答案.看到此代码:

I already got the answer on how to do this in the mongo shell in another Question. See this code:

aggregate([{
    $match: {
        "_id": 1
    }
}, {
    "$project": {
        "_id": 1,
        "sensorName": 1,
        "samplePeriod": 1,
        "data": {
            "$filter": {
                "input": "$data",
                "as": "result",
                "cond": {
                    $and: [{
                        $gte: ["$$result.timestamp", 1483537204000]
                    }, {
                        $lte: ["$$result.timestamp", 1483537214000]
                    }]
                }
            }
        }
    }
}])

但是如何在java spring-data中做到这一点?似乎在spring-data中没有像$ filter这样的东西.有解决方法吗?

But how do I do this in java spring-data? It seems there is nothing like $filter in spring-data. Is there a workaround?

$ filter的效率如何? 您能想到在mongodb中构造此类数据的更有效/更实用的方法吗?

How efficient is $filter anyway? Can you think of a more efficient/practical way of structuring this kind of data in mongodb?

提前谢谢！

推荐答案

您将需要使用spring mongo数据依赖项中提供的MongoTemplate.当前发行版中没有对$ filter的现成支持.利用AggressionExpression.在项目中包括以下投影.使用1.8.5 spring mongo数据版本.

You'll need to make use of MongoTemplate provided in the spring mongo data dependency. There is no out of box support for $filter in the current release version. Make use of AggressionExpression. Include below projection in project. Use 1.8.5 spring mongo data version.

Aggregation aggregation = newAggregation(
        match(Criteria.where("_id").is(1)),
        project( "_id", "sensorName", "samplePeriod").and(new AggregationExpression() {
            @Override
            public DBObject toDbObject(AggregationOperationContext aggregationOperationContext) {
                DBObject filter = new BasicDBObject("input", "$data").append("as", "result").append("cond",
                        new BasicDBObject("$and", Arrays.<Object> asList(new BasicDBObject("$gte", Arrays.<Object> asList("$$result.timestamp", 1483537204000L)),
                                new BasicDBObject("$lte", Arrays.<Object> asList("$$result.timestamp", 1483537214000L)))));
                return new BasicDBObject("$filter", filter);
            }
        }).as("data")
);

List<BasicDBObject> dbObjects = monoTemplate.aggregate(aggregation, "collectionname", BasicDBObject.class).getMappedResults();

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