使用hibernate注释删除父母之间的关系问题

要求是父母被删除时所有相关的孩子必须被删除。当使用hibernate注释删除父母时，我面临删除孩子的问题我的父母表是Employee，子表是EmployeeProject子表具有在数据库Employee_Number一个外键约束，问题是当我删除父以下错误来了，请告诉我是感谢的映射问题使用hibernate注释删除父母之间的关系问题

Hibernate: select employee_.EMPLOYEE_NUMBER, employee_.ADDRESS_1 as ADDRESS2_0_, employee_.ADDRESS_2 as ADDRESS3_0_, employee_.CITY as CITY0_, employee_.DATE_OF_ANNIVERSARY as DATE5_0_, employee_.DATE_OF_BIRTH as DATE6_0_, employee_.DATE_OF_JOINING as DATE7_0_, employee_.DATE_OF_LEAVING as DATE8_0_, employee_.DEPARTMENT_ID as DEPARTMENT9_0_, employee_.FIRST_NAME as FIRST10_0_, employee_.LAST_NAME as LAST11_0_, employee_.MOBILE_NUMBER as MOBILE12_0_, employee_.pincode as pincode0_, employee_.REASON_FOR_LEAVING as REASON14_0_, employee_.state as state0_, employee_.TELEPHONE_NUMBER as TELEPHONE16_0_, employee_.TITLE as TITLE0_ from Employees employee_ where employee_.EMPLOYEE_NUMBER=? 
Hibernate: delete from Employees where EMPLOYEE_NUMBER=? 
4 Mar, 2013 12:33:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions 
WARN: SQL Error: 1451, SQLState: 23000 
4 Mar, 2013 12:33:32 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions 
ERROR: Cannot delete or update a parent row: a foreign key constraint fails (`employee/employee_project`, CONSTRAINT `FKC1804A88229473A9` FOREIGN KEY (`EMPLOYEE_NUMBER`) REFERENCES `employees` (`EMPLOYEE_NUMBER`))

这是我父映射

@OneToMany(mappedBy = "employee", cascade = CascadeType.ALL) 
    Collection<EmployeeProject> employeeProjects = new ArrayList<EmployeeProject>();

这是子表映射

@ManyToOne 
    @JoinColumn(name = "EMPLOYEE_NUMBER", insertable = false, updatable = false) 
    Employee employee;

这是通过该父（雇员）方法被删除

@Override 
public boolean deleteEmployee(Employee employee) { 

    Transaction transaction = null; 
    boolean flag; 
    try { 
     transaction = session.beginTransaction(); 
     session.delete(employee); 
     transaction.commit(); 
     flag = true; 

    } catch (HibernateException exception) { 
     if (transaction != null) 
      transaction.rollback(); 
     flag = false; 
    } 
    return flag; 
}

来源

2013-03-04 henrycharles

确保您在数据库模式中也具有标记为CASCADE的外键关系，假定这是您想要的。 Hibernate的级联将负责删除Hibernate对象，但它本身不会使DELETE将未被转换为对象的子记录截断到您的应用程序中。

来源

2013-03-04 07:22:57

我已经使数据库中的级联和它的工作，但我不明白为什么它显示查询的父只“从员工删除EMPLOYEE_NUMBER = ？”它没有显示删除查询的孩子可以ü请解释它 – henrycharles 2013-03-04 07:32:26

'CASCADE'意味着_the database_在子表上删除你。我猜英语不是你的第一语言？级联是瀑布所做的，所以删除流向子级（和孙级）表。即使您查看服务器上执行的SQL，也不会看到这一点。它被包含在外键关系中，当它被标记为“CASCADE”时。数据库的默认值为'RESTRICT'，如果有子项，则删除被拒绝。你可以自己删除孩子，但效率不高，你不得不担心孙子等。 – 2013-03-04 07:40:43

感谢你解释我很好。 – henrycharles 2013-03-04 08:41:12

尝试此，

  t = session.beginTransaction(); 
     ExperimentImpl persistentExperiment = session.load(Employee.class, 
      employee.getId()); 
    session.delete(persistentExperiment); 
    t.commit();

会尝试使用主键要删除的实验，并在实际删除之前加载：

来源

2013-03-04 07:17:54 PSR

它是为你工作 – PSR 2013-03-04 07:32:20

其工作感谢给我的替代解决方案 – henrycharles 2013-03-04 08:55:15

使用hibernate注释删除父母之间的关系问题

回答

相关问题