定义与Hibernate的关联时出错

我正在尝试使用Hibernate在PostgreSQL数据库中创建两个关联表。我所写的实体是：

@Entity
@Table(name="EMPLOYEE")
public class Employee implements Serializable {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="employee_id")
private Long employeeId;
.
.
.

@ManyToOne
@JoinColumn(name="department_id")
public Department getDepartment() {
    return department;
}

public void setDepartment(Department department) {
    this.department = department;
}

private Department department;

以及：

---

您需要声明成员变量中的所有注释或方法中的所有注释，任何注释都应该有效。在您给出的示例中，您混合了这两者，这就是“无法确定：java.util.Set的类型”的原因。如果需要，可以混合使用@Access（AccessType.FIELD/PROPERTY）

在您的示例中，@OneToMany需要“mappedBy”属性，因为另一个实体中有一个相反的@ManyToOne。mappedBy采用另一个实体中用@ManyToOne注释的字段（或属性）的名称，而不采用数据库中列的名称。这就是错误“mappedBy引用未知的目标实体属性：com.al.hibernatetest.Employee.DEPARTMENT”的原因。异常意味着mappedBy是用大写字母编写的，但该属性在java类中的实际名称似乎是小写字母

---

关于错误“关系部门不存在”，我不知道实体是如何产生的。

我从中获得了实体。他们完全一样。我还注意到，错误出现在输出语句：Hibernate:insert-into-DEPARTMENT（departmentName）值（？）之后，与示例中的预期不同：Hibernate:insert-into-DEPARTMENT（DEPARTMENT_-NAME）值（？）。您提供的链接显示了字段上的所有注释，而方法上没有注释。您可以发布此配置中错误的完整堆栈跟踪吗？还请注意，这些示例没有使用JPA，而是使用旧版本的Hibernate。。。

@Entity
@Table(name="DEPARTMENT")
public class Department implements Serializable {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="DEPARTMENT_ID")
private Long departmentId;

.
.
.
@OneToMany(mappedBy="department")
public Set<Employee> getEmployees() {
    return employees;
}

public void setEmployees(Set<Employee> employees) {
    this.employees = employees;
}


private Set<Employee> employees;

ERROR: FEHLER: Relation »department« existiert nicht
  Position: 13
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:122)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:136)
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:96)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:58)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2967)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3478)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:362)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:203)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:183)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:167)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:321)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:286)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:192)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:205)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:190)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:91)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
    at com.al.hibernatetest.Main.main(Main.java:21)
Caused by: org.postgresql.util.PSQLException: FEHLER: Relation »department« existiert nicht
  Position: 13
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:417)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:363)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:133)
    ... 22 more