外键的列数必须与@ManyToMany链接表的被引用主键的列数相同

Question

我在实体Function和Result之间有多对多的关系，我使用了一个名为Function_produces_result的关联表。

AbstractEntity.java：

@Getter
@Setter
@MappedSuperclass
@EntityListeners(AuditingEntityListener.class)
@ToString
public abstract class AbstractEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
}

FunctionEntity.java：

@Entity
@Table(name = "function")
@Getter
@Setter
public class FunctionEntity extends AbstractEntity {

    private String description;

    @ManyToMany
    @JoinTable(
        name = "function_produces_result",
        joinColumns = @JoinColumn(name = "function_id"),
        inverseJoinColumns = @JoinColumn(name = "result_id")
    )
    Set<ResultEntity> producedResults;
}

FunctionProduceResultEntity.java：

@Entity
@Table(name="function_produces_result")
@Getter
@Setter
public class FunctionProduceResultEntity extends AbstractEntity {
    
    private int rank;

    @ManyToOne
    @JoinColumn(name = "function_id", nullable = false)
    private FunctionEntity function;
    
    @ManyToOne
    @JoinColumn(name = "result_id", nullable = false)
    private ResultEntity result;
}

ResultEntity.java

@Entity
@Table(name = "result")
@Getter
@Setter
public class ResultEntity extends AbstractEntity {

    @Column(nullable = false, unique = true)
    private String code;

    private String name;

    @Column(nullable = false)
    private String type;
}

功能实用性：

@Entity
@Table(name="function_input")
@Getter
@Setter
public class FunctionInputEntity extends AbstractEntity {

    @Enumerated(EnumType.STRING)
    @Column(nullable = false)
    private FunctionInputTypeEnum type;
    
    @ManyToOne
    @JoinColumn(name = "function_id", nullable = false)
    private FunctionEntity function;
    
    @ManyToOne
    @JoinColumn(name = "driver_id")
    private DriverEntity driver;
    
    @ManyToOne
    @JoinColumn(name = "function_result_id")
    private FunctionProduceResultEntity sourceResource;
}

启动服务器时，出现以下错误：

Invocation of init method failed; nested exception is org.hibernate.MappingException: Foreign key (FK4t4snpmx4ck9oj8wkjxvjkg88:function_input [function_result_id])) must have same number of columns as the referenced primary key (function_produces_result [function_id,result_id])
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:342)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:113)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1697)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1442)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:624)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:612)
    at org.springframework.data.repository.config.DeferredRepositoryInitializationListener.onApplicationEvent(DeferredRepositoryInitializationListener.java:51)
    at org.springframework.data.repository.config.DeferredRepositoryInitializationListener.onApplicationEvent(DeferredRepositoryInitializationListener.java:36)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:404)
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:361)
    at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:898)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
    at com.socgen.marvel.ego.Application.main(Application.java:10)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)

还有类似的问题，例如外键必须具有与多对一映射中引用的主键相同的列数，以及Hibernate MappingExc0019：外键必须具有与引用的主键相同的列数，但不能解决我的问题。

Answer 1

您的问题与以下方面有关：

@JoinTable(
            name = "function_produces_result",
            joinColumns = @JoinColumn(name = "function_id"),
            inverseJoinColumns = @JoinColumn(name = "result_id")
    )

您告诉Spring多对多关系是如何开始的FunctionEntitys，但没有提供指令告诉Spring字段result\u id在另一侧映射到什么（即，您没有指定它的结束位置），只是它是多对多关系的一部分。

要解决此问题，您可以将以下内容添加到您的resultantity类定义中：

@ManyToMany(mappedBy = "producedResults")
Set<FunctionEntity> functionEntities = new HashSet<>();

从我在网上看到的来看，它应该是有效的：https://www.infoworld.com/article/3387643/java-persistence-with-jpa-and-hibernate-part-2-many-to-many-relationships.html

Answer 2

问题的根本原因是您试图通过@JoinTable将@manytomy映射与隐藏的链接表以及通过链接实体的映射混为一谈。实际上，您的链接表函数\u生成的\u结果具有id主键，但当您通过@JoinTable注释使用映射时，hibernate假设链接表应具有基于@manytomy关联外键的复合主键。

因此，我建议您按照以下方式重写FunctionEntity实体的映射：

@Entity
@Table(name = "function")
public class FunctionEntity extends AbstractEntity
{
   @OneToMany(mappedBy = "function")
   @MapKey(name = "result")
   private Map<ResultEntity, FunctionProduceResultEntity> producedResults;
}

它将简化从功能实体实体访问结果性实体的过程。

Answer 3

在FunctionInputEntity中，Hibernate需要其中的两个外键引用。你能试试下面的吗？

@ManyToOne
    @JoinColumns({
       @JoinColumn(name = "function_id"),
       @JoinColumn(name = "result_id")
    })
private FunctionProduceResultEntity sourceResource;