在Spring Repository接口中使用sort()和limit()查询 [英] Query with sort() and limit() in Spring Repository interface

问题描述

我是MongoDB的Spring Data的新手，并且想在MongoRepository扩展接口中使用自动生成的查询方法，该方法需要过滤，排序和限制.

I'm new to Spring Data with MongoDB and would like to have an automagically generated query method inside my MongoRepository extension interface which requires filtering, sorting and limiting.

查询如下:

// 'created' is the field I need to sort against

find({state:'ACTIVE'}).sort({created:-1}).limit(1)

存储库界面如下:

public interface JobRepository extends MongoRepository<Job, String> {
    @Query("{ state: 'ACTIVE', userId: ?0 }")
    List<Job> findActiveByUserId(String userId);

    // The next line is the problem, it wont work since
    // it's not in the format @Query expects
    @Query("find({state:'ACTIVE'}).sort({created:-1}).limit(1)")
    Job findOneActiveOldest();

    ...
}

我知道可以将Sort参数添加到查询方法中以获得排序，但是问题是将结果限制为单个对象.不必编写自定义JobRepositoryImpl就能做到吗?

I know that one can add a Sort argument to a query method in order to get sorting but the problem is limiting the results to just a single object. Is this possible to do without having to write a custom JobRepositoryImpl?

谢谢

我正在寻找的示例:

@Query("{ state:'ACTIVE', $orderby: {created:-1}, $limit:1 }")
Job findOneActiveOldest();

或

@Query("{ state:'ACTIVE' }")
@Sort("{ created:-1 }")
@Limit(1)
Job findOneActiveOldest();

但这显然不起作用:(

推荐答案

出了什么问题:

public interface JobRepository extends MongoRepository<Job, String> {

  @Query("{ state : 'ACTIVE' }")
  Page<Job> findOneActiveOldest(Pageable pageable);
}

并使用它:

// Keep that in a constant if it stays the same
PageRequest request = new PageRequest(0, 1, new Sort(Sort.Direction.DESC, "created"));
Job job = repository.findOneActiveOldest(request).getContent().get(0);

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