Question

我使用IN子句使用Hibernate和Spring Data对HSQL查询有一些“SELECT n + 1”问题。

我们有一些组织发布了认为是PublishedApplication对象的应用程序。目前的模型是（并且不能轻易改变）：

public class Application {
    Organization organization;
    ...
}

public class Organization {
    ...
}


public class PublishedApplication extends ... {

    @OneToOne(cascade = CascadeType.ALL, orphanRemoval = true)
    private Application application;

    @ManyToOne(cascade = CascadeType.REFRESH)
    @JoinColumn(name="publishingorganization_uuid")
    protected Organization publishingOrganization;
}

我想列出我的某个组织发布的所有应用。

所以我写这个查询：

@Query(value = "SELECT DISTINCT p.application 
                FROM PublishedApplication p 
                WHERE p.publishingOrganization IN ?1")
 List<Application> findAllByPublishedOrganizationIn(List<Organization> organizations);

这很有效但是当我启用SQL日志时，我看到：

1选择获取“publishedapplication.application”：好的，这是主要请求。
3选择获取“组织”：我可以访问10个组织，但只有3个组织已发布应用程序

以下是代码调用：

log.debug("Before");
List<Application> applications = applicationRepository.findAllByPublishedOrganizationIn(organizations);
log.debug("After");

这是Log：

ApplicationService       : Before

Hibernate: select distinct applicatio1_.uuid as uuid1_0_, applicatio1_.version as version2_0_, applicatio1_.description as descript3_0_, applicatio1_.lastversiondate as lastvers4_0_, applicatio1_.name as name5_0_, applicatio1_.organization_uuid as organiza6_0_ from publishedapplication publisheda0_ inner join applications applicatio1_ on publisheda0_.application_uuid=applicatio1_.uuid where publisheda0_.publishingorganization_uuid in (? , ? , ? , ? , ? , ? , ? , ? , ? , ?)
Hibernate: select organizati0_.uuid as uuid1_8_0_, organizati0_.version as version2_8_0_, organizati0_.description as descript3_8_0_, organizati0_.name as name4_8_0_ from organizations organizati0_ where organizati0_.uuid=?
Hibernate: select organizati0_.uuid as uuid1_8_0_, organizati0_.version as version2_8_0_, organizati0_.description as descript3_8_0_, organizati0_.name as name4_8_0_ from organizations organizati0_ where organizati0_.uuid=?
Hibernate: select organizati0_.uuid as uuid1_8_0_, organizati0_.version as version2_8_0_, organizati0_.description as descript3_8_0_, organizati0_.name as name4_8_0_ from organizations organizati0_ where organizati0_.uuid=?

ApplicationService       : After

我认为3'SELECT组织'是通过执行“p.publishingOrganization IN”触发的。这是使用单个SELECT解决此问题的方法吗？ SQL中的这样的东西：

List<Organization> orgs = ...
List<String> orgsIds = ...
doSQL("SELECT * 
       FROM publishedApplication p 
       WHERE p.publishingOrganizationId IN (" + orgsIds.join(",") + ")");

由于

编辑：我使用以下方法解决此问题：

SELECT DISTINCT p.application FROM PublishedApplication p JOIN FETCH p.application.organization WHERE p.publishingOrganization IN ?1

使用IN

0 个答案: