如何使用 nativeQuery 和 Spring PagingAndSortingRepository 在 JPA 中分页查询答案

【问题标题】：How to paging a query in JPA with nativeQuery and Spring PagingAndSortingRepository如何使用 nativeQuery 和 Spring PagingAndSortingRepository 在 JPA 中分页查询
【发布时间】：2019-10-03 20:29:50
【问题描述】：

前几天有同事提出这个问题：Order and group by with one column

已解决。一个简单干净的查询，很酷。这个解决方案似乎是值得的，只是我们需要在 JPA 中实现它。

由于 JPA 不接受 JOIN 中的子查询，因此我们必须将其作为 nativeQuery 进行，但这样做会遇到分页问题，因为 JPA 不会将其与本机查询结合使用。 https://docs.spring.io/spring-data/jpa/docs/1.8.0.M1/reference/html/

原生查询@Query 注解允许执行原生查询通过将 nativeQuery 标志设置为 true。请注意，我们目前不支持对本机查询执行分页或动态排序因为我们必须操纵声明的实际查询，我们不能这样做这对于原生 SQL 来说是可靠的。

我们不知道如何继续。

我们要做的：我们有电话号码、用户和日期的一系列记录，每个用户都可以拨打N次。我们需要获取所有按电话号码分组的记录，并按每组号码的最近日期排序（DESC）。

例如：

有了这些数据：

+--------------+---------------------+-------------+---------------+
| phone_number | registered          | name        | first_surname |
+--------------+---------------------+-------------+---------------+
|    222005001 | 2019-05-10 10:01:01 | Alvaro      | Garcia        |
|    222004001 | 2019-05-13 16:14:21 | David       | Garcia        |
|    111003001 | 2019-05-13 16:14:43 | Roberto     | Martin        |
|    111001000 | 2019-05-13 16:14:50 | Juan Manuel | Martin        |
|    111001000 | 2019-05-13 16:14:50 | Maria       | Alonso        |
|    111001000 | 2019-05-13 16:14:50 | Roberto     | Martin        |
|    333006001 | 2019-05-13 16:14:55 | Benito      | Lopera        |
|    123456789 | 2019-05-13 16:15:00 | NULL        | NULL          |
|    987654321 | 2019-05-13 16:15:08 | NULL        | NULL          |
|    123456789 | 2019-05-13 16:15:13 | NULL        | NULL          |
|    666999666 | 2019-05-13 16:15:18 | NULL        | NULL          |
|    454545458 | 2019-05-13 16:15:27 | NULL        | NULL          |
|    333006001 | 2019-05-13 16:23:36 | Benito      | Lopera        |
|    987654321 | 2019-05-13 16:23:46 | NULL        | NULL          |
|    666999666 | 2019-05-13 16:23:50 | NULL        | NULL          |
|    454545458 | 2019-05-13 16:23:55 | NULL        | NULL          |
|    666999666 | 2019-05-13 16:24:03 | NULL        | NULL          |
|    222004001 | 2019-05-13 16:24:10 | David       | Garcia        |
+--------------+---------------------+-------------+---------------+

像这样对它们进行排序：

+--------------+---------------------+-------------+---------------+
| phone_number | registered          | name        | first_surname |
+--------------+---------------------+-------------+---------------+
|    222004001 | 2019-05-13 16:24:10 | David       | Garcia        |
|    222004001 | 2019-05-13 16:14:21 | David       | Garcia        |
|    666999666 | 2019-05-13 16:24:03 | NULL        | NULL          |
|    666999666 | 2019-05-13 16:23:50 | NULL        | NULL          |
|    666999666 | 2019-05-13 16:15:18 | NULL        | NULL          |
|    454545458 | 2019-05-13 16:23:55 | NULL        | NULL          |
|    454545458 | 2019-05-13 16:15:27 | NULL        | NULL          |
|    987654321 | 2019-05-13 16:23:46 | NULL        | NULL          |
|    987654321 | 2019-05-13 16:15:08 | NULL        | NULL          |
|    333006001 | 2019-05-13 16:23:36 | Benito      | Lopera        |
|    333006001 | 2019-05-13 16:14:55 | Benito      | Lopera        |
|    123456789 | 2019-05-13 16:15:13 | NULL        | NULL          |
|    123456789 | 2019-05-13 16:15:00 | NULL        | NULL          |
|    111001000 | 2019-05-13 16:14:50 | Maria       | Alonso        |
|    111001000 | 2019-05-13 16:14:50 | Roberto     | Martin        |
|    111001000 | 2019-05-13 16:14:50 | Juan Manuel | Martin        |
|    111003001 | 2019-05-13 16:14:43 | Roberto     | Martin        |
|    222005001 | 2019-05-10 10:01:01 | Alvaro      | Garcia        |
+--------------+---------------------+-------------+---------------+

可以用这个查询来完成：

SELECT c.phone_number, c.registered, cl.name, cl.first_surname
FROM callers cl
    INNER JOIN callers_phones cp ON cl.caller_id = cp.caller_id
    RIGHT OUTER JOIN calls c ON c.phone_number = cp.phone_number
    JOIN (
        SELECT phone_number, MAX(registered) AS registered
        FROM calls
        GROUP BY phone_number) aux_c ON aux_c.phone_number = c.phone_number
WHERE c.answered = FALSE
    AND (null is null or null is null or c.registered between null and null)
    AND (null is null or c.phone_number = null)
    AND (null is null or cl.caller_id = null)
ORDER BY aux_c.registered DESC, c.registered DESC

这些是表格：

CREATE TABLE callers
(
    caller_id int NOT NULL UNIQUE AUTO_INCREMENT,
    name varchar(50) NOT NULL,
    first_surname varchar(50) NOT NULL,
    CONSTRAINT callers_pkey PRIMARY KEY (caller_id)
);

CREATE TABLE callers_phones
(
    phone_id int NOT NULL UNIQUE AUTO_INCREMENT,
    caller_id int NOT NULL,
    phone_number int NOT NULL,
    CONSTRAINT callers_phones_pkey PRIMARY KEY (phone_id)
);

ALTER TABLE callers_phones
    ADD CONSTRAINT callers_phones_fkey_callers FOREIGN KEY (caller_id)
    REFERENCES callers (caller_id);

CREATE TABLE calls
(   
    call_id int NOT NULL UNIQUE AUTO_INCREMENT,
    phone_number int NOT NULL,
    answered boolean NOT NULL DEFAULT false,
    registered datetime NOT NULL,
    CONSTRAINT calls_pkey PRIMARY KEY (call_id)
);

问题是我们必须在 JPA 中使用分页来实现它，但是子查询在 JOIN 子句中不起作用，并且分页不适用于 nativeQuery。

这就是我们所做的：

@实体：

import java.util.Date;

import javax.persistence.Entity;
import javax.persistence.EntityResult;
import javax.persistence.FieldResult;
import javax.persistence.Id;
import javax.persistence.NamedNativeQuery;
import javax.persistence.SqlResultSetMapping;

@SqlResultSetMapping (name = "MissedCallResult",
        entities = {
                     @EntityResult (entityClass = MissedCallEntity.class,
                             fields = {
                                        @FieldResult (name = "callId", column = "id"),
                                        @FieldResult (name = "phoneNumber", column = "pH"),
                                        @FieldResult (name = "registered", column = "reg"),
                                        @FieldResult (name = "callerName", column = "cN"),
                                        @FieldResult (name = "callerFirstSurname", column = "cFS")
                             })
        })
@NamedNativeQuery (name = "findMissedCalls",
        query = "select c.call_id as id, c.phone_number as pH, c.registered as reg, cl.name as cN, cl.first_surname as cFS "
                + "from callers cl "
                + "    inner join callers_phones cp on cl.caller_id = cp.caller_id "
                + "    right outer join calls c on c.phone_number = cp.phone_number "
                + "    join (select c2.phone_number, MAX(c2.registered) as registered "
                + "        from calls c2 "
                + "        group by c2.phone_number) aux_c on aux_c.phone_number = c.phone_number "
                + "where c.answered = false "
                + "    and (:startDate is null or :endDate is null or c.registered between :startDate and :endDate) "
                + "    and (:callerId is null or cl.caller_id = :callerId) "
                + "    and (:phoneNumber is null or c.phone_number = :phoneNumber) "
                + "order by aux_c.registered desc, c.registered desc",
        resultSetMapping = "MissedCallResult")
@Entity
public class MissedCallEntity
{
    @Id
    private Integer callId;
    private Integer phoneNumber;
    private Date registered;
    private String callerName;
    private String callerFirstSurname;
    private String callerSecondSurname;

...

}

@Repository：

import java.util.Date;

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;

import es.panel.domain.MissedCallEntity;

@RepositoryRestResource (path = "missedCalls", collectionResourceRel = "missedCalls")
public interface MissedCallRepository extends PagingAndSortingRepository<MissedCallEntity, Integer>
{
    @Query (nativeQuery = true, name = "findMissedCalls")
    Page<MissedCallEntity> findMissedCalls(@Param ("startDate") Date startDate,
                                           @Param ("endDate") Date endDate,
                                           @Param ("callerId") Integer callerId,
                                           @Param ("phoneNumber") Integer phoneNumber,
                                           Pageable page);
}

在@Service 中：

public Page<MissedCallEntity> getMissedCalls(Date startDate,
                                                 Date endDate,
                                                 Integer callerId,
                                                 Integer phoneNumber,
                                                 int actualPage,
                                                 int limit)
    {
        Page<MissedCallEntity> calls = mcRepository.findMissedCalls(
                startDate, endDate, callerId, phoneNumber, PageRequest.of(1, 5));

        return calls;
    }

提前致谢！

【问题讨论】：

标签： mysql spring-data-jpa

【解决方案1】：

一个非常简单的解决方案是根据您对计算值（即计数和最大值等）的查询创建一个数据库视图。

您可以使用 JPA @SecondaryTable 注释将其映射到相关实体，该注释可让您将实体映射到多个表（或视图）。

在这里，您可以使用标准 JPA/spring 数据功能进行排序和过滤，就像处理任何其他字段一样，您几乎可以删除您编写的所有代码。

我会进一步详细说明，但是您要实现的目标不是很清楚：您询问的是您尝试的解决方案，而不是问题本身。 MissedCall 也不是实体。您系统中的实体是用户、呼叫、电话等。

【讨论】：