Question

我有3个实体 - Storage，Item和Relation。 Storage有几个Item个实体，项目由Relation个实体绑定。关系可以绑定来自不同存储的项目。为简化起见，我想通过查询加载关系并希望快速完成。所以现在我有3个查询 - 加载Storage，加载存储和加载关系（List<Relation> relations字段）下的所有项目。

现在我想告诉hibernate如何加载Collection<Relation> extRelation字段。我尝试了@Formula，@CalculatedColumn以及@ManyToMany和@JoinFormula的不同组合。但生成的查询是错误的（或忽略我的查询）。另外，由于https://hibernate.atlassian.net/browse/HHH-9897错误，我无法使用@OneToMany。

最新例外是：

引起：org.h2.jdbc.JdbcSQLException：表未找到“TEST_STORAGES_TEST_RELATIONS”; SQL语句：

SELECT extrelatio0_.test_storages_storage_id AS test_sto1_2_0_
 ,extrelatio0_.extRelation_from_item_id AS extRelat2_3_0_
 ,extrelatio0_.extRelation_to_item_id AS extRelat3_3_0_
 ,relation1_.from_item_id AS from_ite1_1_1_
 ,relation1_.to_item_id AS to_item_2_1_1_
 ,relation1_.relation_id AS relation3_1_1_
 ,relation1_.storage_id AS storage_4_1_1_
FROM test_storages_test_relations extrelatio0_
INNER JOIN test_relations relation1_ ON extrelatio0_.extRelation_from_item_id = relation1_.from_item_id
 AND extrelatio0_.extRelation_to_item_id = relation1_.to_item_id
WHERE extrelatio0_.test_storages_storage_id = ?

我的实体：

@Entity
@Table(name = "test_storages")
public class Storage {

    @Id
    @Column(name = "storage_id")
    private BigInteger storageId;

    private String name;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, orphanRemoval = true, targetEntity = Item.class)
    @JoinColumn(name = "storage_id", updatable = false)
    @MapKey
    private List<Item> items;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, orphanRemoval = true, targetEntity = Relation.class)
    @JoinColumn(name = "storage_id", updatable = false)
    @Fetch(org.hibernate.annotations.FetchMode.SELECT)
    private List<Relation> relations;

    @ManyToMany()
    @JoinColumnsOrFormulas({
        @JoinColumnOrFormula(formula =
            @JoinFormula(
                    value = "(select dep.from_item_id, dep.to_item_id from test_relations dep where dep.storage_id = ?)"
            )
        )
    })
    private Collection<Relation> extRelation;
}

@Entity
@Table(name = "test_items")
public class Item {

    @Id
    @Column(name = "item_id")
    private BigInteger itemId;

    private String name;

    @Column(name = "storage_id")
    private BigInteger storageId;
}

@Entity
@Table(name = "test_relations")
public class Relation {
    @Column(name = "relation_id")
    private BigInteger relationId;

    @Column(name = "storage_id")
    private BigInteger storageId;

    @EmbeddedId
    private RelationPK pk;
}

@Embeddable
public class RelationPK implements Serializable {
    @Column(name = "from_item_id")
    private BigInteger fromItemId;

    @Column(name = "to_item_id")
    private BigInteger toItemId;
}

https://github.com/ainlolcat/test_hibernate_formula

上提供的所有来源

使用Hibernate Formula注释进行参考加载

0 个答案: