在我的Spring MVC应用程序(休眠版本:4.1.7.final)中,我有一个包含多头列表的实体,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)
怎么了我怎样才能做到这一点?
最佳答案
为了实现您想要的查询类型(针对@ElementCollection
的内容),您将需要更改为@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
的局限性在于,无法独立于其父对象来查询,持久化和合并目标对象。它们是严格私有(依赖)的对象,与@Embedded
映射相同。 @ElementCollection
上没有层叠选项,目标对象始终与其父对象保持,合并或删除。 @ElementCollection
仍然可以使用访存类型,并且默认为LAZY,与其他集合映射相同。