Spring Data elasticsearch @Query annotation for nested objects

问题

I have two class,

@Document
public class PracticeQuestion {

     private int userId;
     private List<Question> questions;

// Getters and setters
}


public class Question {

     private int questionID;
     private String type;

// Getters and setters
}

My JSON doc is like this,

{
"_id" : ObjectId("506d9c0ce4b005cb478c2e97"),
"userId" : 1,
"questions" : [
    {
        "questionID" : 1,
        "type" : "optional"

    },
    {
        "questionID" : 3,
        "type" : "mandatory"

    }
]
}

How should I write the query method to find PracticeQuestion by userId and questionID using @Query annotation.

Thanks for any suggestion.

回答1:

If you want to search by userId and QuestionId. You have 2 options.

Use nested queries (Questions in the example above is kind of a nested object and elasticsearch support search on nested objects.). You can read more about it here.

You can create PracticeQuestionRepository with a method findByUserId like shown below.

public interface PracticeQuestionRepository extends ElasticsearchRepository<PracticeQuestion, String> {
    @Query("{"query":{"bool":{"must":[{"match":{"userId":"?0"}},{"nested":{"path":"questions","query":{"bool":{"must":[{"match":{"questions.id":"?1"}}]}}}}]}}}")"
    Page<PracticeQuestion> findByUserIdAndQuestionId(String userId, String questionId, Pageable pageable);
}

If you do not want to use nested objects. De normalize the schema and flatten the question and userId at the same level and then issue a query on userId and QuestionId.

e.g. Document 1

{
    "_id": "506d9c0ce4b005cb478c2e97",
    "userId": 1,
    "questionID": 1,
    "type": "optional"
}

Document 2

{
    "_id": "506d9c0ce4b005cb478c2e97",
    "userId": 1,
    "questionID": 1,
    "type": "optional"
}

Code for Repository

public interface PracticeQuestionRepository extends ElasticsearchRepository<PracticeQuestion, String> {
    @Query("{"bool" : {"must" : [ {"field" : {"userId" : "?0"}}, {"field" : {"questionId" : "?1"}} ]}}"")
    Page<PracticeQuestion> findByUserIdAndQuestionId(String userId, String questionId, Pageable pageable);
}

Refer this link for more examples

来源：https://stackoverflow.com/questions/27374618/spring-data-elasticsearch-query-annotation-for-nested-objects

标签

java

ElasticSearch

spring-data-elasticsearch