lookup与getmappedresults()一起使用时无法正常工作

1l5u6lss  于 2021-07-26  发布在  Java
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我有以下代码,其答案为 getRawResult 以及 getMappedResult 它们是不同的。我想知道怎样才能包括 user 以及 place mappedresults中的对象。

// This methd searches the given string in reviews of the given country

        MatchOperation matchRegion = Aggregation.match(Criteria.where("Country").is("Germany"));

        //To match the review
        TextCriteria criteria = TextCriteria.forDefaultLanguage().matchingAny(text);
        MatchOperation match = Aggregation.match(criteria);         

        GroupOperation group = Aggregation.group("place.place_name").push("$$ROOT").as("reviews").sum("textScore")
                .as("score");

        ProjectionOperation project = Aggregation
                .project("some_point", "place", "user", "date")
                .andExpression("{$meta: \"textScore\"}").as("textScore");               

        SortOperation sortByScore = Aggregation.sort(Sort.Direction.DESC, "score");

        Aggregation aggregation = Aggregation.newAggregation(match,Aggregation.lookup("place","placeId","_id","place"),
                Aggregation.unwind("place"),Aggregation.lookup("user","userId","_id","user"),
                Aggregation.unwind("user") , matchRegion, project, group, sortByScore);

        AggregationResults<ReviewAggrResults> results = mongoTemplate.aggregate(aggregation,
                mongoTemplate.getCollectionName(Review.class), ReviewAggrResults.class);    

        List<ReviewAggrResults> result = results.getMappedResults();

        Object object = mongoTemplate.aggregate(aggregation, Review.class, Object.class).getRawResults();

        Print.print("result object rawResults", object); 
        Print.print("result reviewaggrresult: ", result);

使用上述代码,打印的结果 getRawResults 以及 ReviewAggrResult 如下所示:
原始结果:

{
      "results" : [ {
        "_id" : "ibis Heidelberg, Willy-Brandt-Platz 3, 69115 Heidelberg, Germany",
        "reviews" : [ {
          "_id" : {
            "timestamp" : 1610817567,
            "date" : 1610817567000
          },
          "some_point" : "something",         
          "date" : "Sat Jan 16 18:19:27 CET 2021",
          "place" : {
            "_id" : {
              "timestamp" : 1610817567,
              "date" : 1610817567000
            },
            "place_name" : "ibis Heidelberg, Willy-Brandt-Platz 3, 69115 Heidelberg, Germany",
            "country" : "Germany",
          },
          "user" : {
            "_id" : {
              "timestamp" : 1610817549,
              "date" : 1610817549000
            },
            "firstname" : "test1first",
            "lastname" : "test1last",
          },
          "textScore" : 5.25
        } ],
        "score" : 5.25
      } ],
      "ok" : 1.0
    }

Map结果:

[ {
  "reviews" : [ {
    "id" : "6003201f98afbc730e4f58eb",
    "some_point" : "something",
    "placeId" : null,
    "userId" : null,
    "date" : "Sat Jan 16 18:19:27 CET 2021",
    "textScore" : 5.25
  } ],
  "id" : "ibis Heidelberg, Willy-Brandt-Platz 3, 69115 Heidelberg, Germany",
  "userId" : null,
  "user" : null,
  "score" : 5.25
} ]

为什么它们不同?原始结果是正确的,但是当它被Map时,place和user对象被移除。如何将它们也包含在mappedresult中?

bqf10yzr

bqf10yzr1#

getMappedResults() 提供到Map类和聚合结果的直接Map。看看这里怎么了。当你采取 getRawResult() ,我只举一个例子 place"place" : { "_id" : { "timestamp" : 1610817567, "date" : 1610817567000 }, "place_name" : "ibis Heidelberg, Willy-Brandt-Platz 3, 69115 Heidelberg, Germany", "country" : "Germany", }place 是一个具有 _id , place_name 以及 country . 但在你的班级里 Review ,你只有 placeId 不是由结果提供的。所以它不能做点对点的Map。你能做的就是

class Place{
    ObjectId _id;
    String place_name;
    String country;
    //Constrtuctors, Getters, Setters
}

在复习课上,

class Review{
    // other fields
    Place place;
}

您还需要对其他对象或数组执行相同的操作。这应该管用

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