java - Hibernate 级联删除未按预期工作

Question

我正在使用 hibernate 3 并试图删除数据库中的一条记录，但删除没有像我预期的那样工作。 hibernate 模式正在针对(伪代码):

create table Employer(
    employer_id number(12) primary key,
    employer_name varchar2(50)
);

create table Employee(
    employee_id number(12) primary key,
    employee_name varchar2(50),
    employer_id number(12) foreign key references employer.employer_id not null
);

create table Employee_Roles(
    role_id number(12) primary key,
    employee_id number(12) foreign key references employee.employee_id not null,
    role varchar2(50)
);

我的 hibernate 类映射类似于:

@Entity
public class Employer{

    @Id
    @Column(name = "EMPLOYER_ID")
    private long id;

    @Column
    private String name;


    @OneToMany(targetEntity = Employee.class, fetch = FetchType.EAGER)
    @JoinColumn(name = "employer_id")
    @Cascade(CascadeType.ALL)
    private Set<Employee> employees;
}

@Entity
public class Employee{

    @ManyToOne(targetEntity = Employer.class)
    @JoinColumn(name = "employer_id")
    @Cascade(value = CascadeType.SAVE_UPDATE)
    private Employer employer;

    @OneToMany(targetEntity = EmployeeRole.class, fetch = FetchType.EAGER)
    @JoinColumn(name = "employee_id")
    @Cascade(CascadeType.ALL)
    private Set<Employee> employees;
}

@Entity
public class EmployeeRole{

    @ManyToOne(targetEntity = Employee.class)
    @JoinColumn(name = "employee_id")
    @Cascade(value = CascadeType.SAVE_UPDATE)
    private Employee employee;
}

现在我调用这个配置:

getCurrentSession().delete(someEmployerEntity);

发生的事情是:

Hibernate: update EMPLOYEE set EMPLOYEE_ID=null where EMPLOYEE_ID=?
Hibernate: update EMPLOYEE_ROLE set employee_id=null where employee_id==?
[2011-04-15 15:59:53,487] JDBCExceptionReporter WARN  - SQL Error: -10, SQLState: 23502
[2011-04-15 15:59:53,487] JDBCExceptionReporter ERROR - integrity constraint violation: NOT NULL check constraint; SYS_CT_10058 table: EMPLOYEE_ROLE

并引发异常。我期望 session.remove(..) 调用的结果是要删除的雇主记录，以及与雇主关联的所有员工记录和与已删除员工记录关联的所有 EmployeeRole 记录。这是一个正确的假设吗？还是我误解了这里的一个关键概念？

Answer 1

Cascade all-delete-orphan 应该可以解决您的问题。但是，它是 Hibernate 的一部分，而不是 EJB 标准。如果您想这样做并且不想被供应商的解决方案所困，我建议您看看 this article .

祝你好运!

编辑:根据您的建议，我将“mappedBy”属性添加到@OneToMany 注释中，这似乎是使用 inverse="true"指定拥有关系的注释方式。关系的相关更改部分如下所示:

public class Employee{

    @OneToMany(targetEntity = EmployeeRole.class, mappedBy="employee", fetch = FetchType.EAGER,  cascadeType=CascadeType.ALL)
    private Set<EmployeeRole> employeeRoles;
}


public class Employer{

    @OneToMany(targetEntity = Employee.class, mappedBy="employer", fetch = FetchType.EAGER, cascadeType=CascadeType.ALL)
    private Set<Employee> employees;
}