java - 多对多 JPA Hibernate 通过连接表映射复合键错误

Question

我有以下两个带有这些注释的类(及其 pk 类)。我删除了 setters/getters/hashcode/equals 来压缩示例

我最终收到了这个错误

org.hibernate.MappingException:集合映射中的重复列:com.stackOverflow.Features.thingCategory列:YEAR

我的猜测是，因为“年份”在连接表中共享，所以我搞乱了一些关联实体的语法。请注意，这些 View 在其实体之间具有隐式关系，我试图在注释中对其进行建模。我尝试过一些 JPA 建模工具，这些工具在建模后给我同样的错误。我也尝试将连接列设置为 insertable 和 updatable 为 false 。

我当然可以只编写一个 SQL 查询，但我真的很惊讶在 Hibernate 中这对我来说有多难。

功能实体

@Entity
@Table(name = "myTableOfFeatures")
public class Feature {
    private static final long serialVersionUID = 1L;

    @EmbeddedId
    private FeatureKey id;

    @Column(name="displayText")
    private String description;

    //bi-directional many-to-many association
    @ManyToMany
    @JoinTable(
            name="joinTableToThingCategories"
            , joinColumns={
            @JoinColumn(name="name", referencedColumnName="name", insertable = false, updatable = false),
            @JoinColumn(name="year", referencedColumnName="year", insertable = false, updatable = false)
    }
            , inverseJoinColumns={
            @JoinColumn(name="year", referencedColumnName="year", insertable = false, updatable = false),
            @JoinColumn(name="title", referencedColumnName="title", insertable = false, updatable = false)
    }
    )
    private List<ThingCategory> thingCategory;

    public Feature() {
    } 
    // ... gets and sets

} 
@Embeddable
public class FeatureKey implements Serializable {
    //default serial version id, required for serializable classes.
    private static final long serialVersionUID = 1L;

    @Column(name="name")
    private String myName;

    private String year;

    public FeatureKey() {
    }
    // ... gets and sets and equals and hashes
}

事物类别实体

@Entity
@Table(name = "CategoriesOfThings")
public class ThingCategory implements Serializable {
    private static final long serialVersionUID = 1L;

    @EmbeddedId
    private ThingCategoryKey id;

    private String comment;

    //bi-directional many-to-many association to categories
    @ManyToMany(mappedBy="thingCategory")
    private List<Feature> features;

    public ThingCategory() {
    }
    // ... gets and sets
}
@Embeddable
public class ThingCategoryKey implements Serializable {
    //default serial version id, required for serializable classes.
    private static final long serialVersionUID = 1L;

    private String year;

    @Column(name="categoryName")
    private String title;

    public ThingCategoryKey() {
    }
    // ... gets and sets and equals and hashes
}

Answer 1

这是 JPA 2.1 规范的示例。 我希望它有帮助。

@Entity
public class Employee {
    @Id int id;
    @Embedded ContactInfo contactInfo;
    ...
}


@Embeddable
public class ContactInfo {
    @ManyToOne Address address; // Unidirectional
    @ManyToMany List<PhoneNumber> phoneNumbers; // Bidirectional 
}

@Entity
public class PhoneNumber {
    @Id int phNumber; 

    @ManyToMany(mappedBy="contactInfo.phoneNumbers")         
    Collection<Employee> employees;
}

我强烈推荐您这个规范。 JPA 2.1