JPA Criteria API - 查询代码在单独执行时有效，但在用作子查询时无效

Question

我有实体 Issue 和实体 UserIssue。 UserIssue 扩展 Issue.

@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@Where(clause = "DELETED_AT IS NULL")
@Entity(name = "ISSUE")
public class Issue extends VersionedSequenceIdEntity {
... all fields
}

@Where(clause = "DELETED_AT IS NULL")
@Entity(name = "USER_ISSUE")
public class UserIssue extends Issue {

    ...

    @Column(name = "IS_PRIVATE", nullable = false)
    private Boolean isPrivate;

    ...
}

我正在执行子查询以通过 sublcass 属性进行一些过滤。我的确切测试用例是我创建了三个 UserIssues。其中两个将“isPrivate”属性设置为 false。第三个是 isPrivate on true.

当我执行这个实际上只是子查询的代码时，结果包含两个基于条件的“问题”并且它是正确的

CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery<UserIssue> issueQuerySimple = cb.createQuery(UserIssue.class);
Root<UserIssue> issueRootSimple = issueQuerySimple.from(UserIssue.class);

issueQuerySimple.select(issueRootSimple).where(cb.isFalse(issueRootSimple.get("isPrivate")));
List<UserIssue> resultListSimple = entityManager.createQuery(issueQuerySimple).getResultList();

但是当我在上面的代码用作子查询的情况下构建整个查询时，所有三个“问题”都被 returned 并且出现了问题。我希望代码再次 return 只有两个将“isPrivate”属性设置为 false

的“问题”

CriteriaQuery<Issue> issueQuery = cb.createQuery(Issue.class);
Root<Issue> issueRoot = issueQuery.from(Issue.class);

Subquery<UserIssue> subQuery = issueQuery.subquery(UserIssue.class);
Root<UserIssue> userIssueRoot = subQuery.from(UserIssue.class);

subQuery.select(userIssueRoot).where(cb.isFalse(userIssueRoot.get("isPrivate")));

issueQuery.select(issueRoot).where(cb.exists(subQuery));
List<Issue> resultList = entityManager.createQuery(issueQuery).getResultList();

在这里您还可以看到来自休眠创建的日志的查询。这对我来说似乎是正确的

select
        issue0_.id as id2_2_,
        issue0_.deleted_at as deleted_3_2_,
        issue0_.created_when as created_4_2_,
        issue0_.created_by as created_5_2_,
        issue0_.updated_when as updated_6_2_,
        issue0_.version as version7_2_,
        issue0_.application_id as applicat8_2_,
        issue0_.version_id as version_9_2_,
        issue0_.organization_id as organiz10_2_,
        issue0_.severity as severit11_2_,
        issue0_.state as state12_2_,
        issue0_.title as title13_2_,
        issue0_.type_id as type_id18_2_,
        issue0_.updated_by_customer_at as updated14_2_,
        issue0_.assigned_to as assigne15_2_,
        issue0_.description as descrip16_2_,
        issue0_.is_private as is_priv17_2_,
        issue0_.dtype as dtype1_2_ 
    from
        issue issue0_ 
    where
        (
            issue0_.DELETED_AT IS NULL
        ) 
        and (
            exists (
                select
                    userissue1_.id 
                from
                    issue userissue1_ 
                where
                    userissue1_.dtype='UserIssue' 
                    and (
                        userissue1_.DELETED_AT IS NULL
                    ) 
                    and userissue1_.is_private=0
            )
        )

那么，为什么基于子类字段的过滤不起作用，它 return 是所有三个实例而不是两个？有什么问题或我看不到什么？

非常感谢

Answer 1

替换

issueQuery.select(issueRoot).where(cb.exists(subQuery));

和

issueQuery.select(issueRoot).where(issueRoot.get("id").in(subQuery));

说明

从sql查询可以看出，只要一个userissue和is_private=0存在，就会select 所有 issues
这不是您想要的行为。您仍然必须使用子查询，但想用 issue0_.id in 替换 exists 并且此代码片段会执行此操作

JPA Criteria API - 查询代码在单独执行时有效，但在用作子查询时无效

JPA Criteria API - query code works when executed separately but not when used as a subquery

java

hibernate

jpa

criteria-api