java - JPQL 查询 - 实体包含多头列表

Question

在我的 Spring MVC 应用程序(Hibernate 版本:4.1.7.final)中，我有一个包含长整数列表的实体，如下所示:

@Entity
@Table(name = "foo")
public class Foo {
    @Id
    private Long id;

    @ElementCollection
    @CollectionTable(
            name = "foo_numbers",
            joinColumns = {@JoinColumn(
                    name = "foo_id",
                    referencedColumnName = "id")})
    private Collection<Long> numbers;

    ...
}

目标是为那些列表为空或包含给定数字的 Foos 编写查询，例如:

@Query("SELECT f FROM Foo AS f WHERE f.numbers IS EMPTY OR (:num) MEMBER OF f.numbers")
Collection<Foo> findTheRightFoos(@Param("num") Long num);

但是我遇到了以下问题:

@Query("SELECT f FROM Foo AS f WHERE (:num) MEMBER OF f.numbers")
Collection<Foo> findFoos_1(@Param("num") Long num);
//org.springframework.orm.jpa.JpaSystemException: org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '))' at line 1; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '))' at line 1
//Hibernate log: select fooba0_.id as id9_ from foo fooba0_ cross join foo_numbers numbers1_ where fooba0_.id=numbers1_.foo and (? in (.))

@Query("SELECT f FROM Foo AS f WHERE (:num) IN f.numbers")
Collection<Foo> findFoos_2(@Param("num") Long num);
//Can't start the app, got the following exception:
//antlr.NoViableAltException: unexpected end of subtree ...
//... Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected end of subtree [SELECT c FROM com.acme.Foo AS f WHERE (:num) IN f.numbers]

@Query("SELECT f FROM Foo AS f WHERE f.numbers = (:num)")
Collection<Foo> findFoos_3(@Param("num") Long num);
//org.springframework.dao.InvalidDataAccessApiUsageException: Parameter value [3870] did not match expected type [java.util.Collection]; nested exception is java.lang.IllegalArgumentException: Parameter value [3870] did not match expected type [java.util.Collection]

@Query("SELECT f FROM Foo AS f WHERE f.numbers IS EMPTY")
Collection<Foo> findFoos_4();
//Can't start the app, got the following exception:
//antlr.NoViableAltException: unexpected end of subtree ...
//... Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected end of subtree [SELECT c FROM com.acme.Foo AS f WHERE f.numbers IS EMPTY]

@Query("SELECT f FROM Foo AS f WHERE f.numbers IS NULL")
Collection<Foo> findFoos_5();
//org.springframework.orm.jpa.JpaSystemException: org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'is null)' at line 1; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'is null)' at line 1
//Hibernate log: select fooba0_.id as id9_ from foo fooba0_ cross join foo_numbers numbers1_ where fooba0_.id=numbers1_.foo and (. is null)

@Query("SELECT f FROM Foo AS f WHERE f.numbers = NULL")
Collection<Foo> findFoos_6();
//org.springframework.orm.jpa.JpaSystemException: org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'is null)' at line 1; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'is null)' at line 1
//Hibernate log same as 'findFoos_5': select fooba0_.id as id9_ from foo fooba0_ cross join foo_numbers numbers1_ where fooba0_.id=numbers1_.foo and (. is null)

这有什么问题？我该怎么做？

Answer 1

要实现您想要的查询类型(针对 @ElementCollection 的内容)，您需要更改为 @OneToMany 关联。这是我的支持(来自JPA: When to choose Multivalued Association vs. Element Collection Mapping)

使用 @ElementCollection 而不是 @OneToMany 的限制是目标对象无法独立于其父对象进行查询、持久化和合并。它们是严格私有(private)(依赖)的对象，与 @Embedded 映射相同。 @ElementCollection 上没有级联选项，目标对象始终与其父对象一起持久化、合并、删除。 @ElementCollection 仍然可以使用获取类型并默认为 LAZY，与其他集合映射相同。