时间戳

首页 > 解决方案 > JPA/Hibernate 事务问题

hibernate - JPA/Hibernate 事务问题

问题描述

我希望我可以使用选项 TABLE 生成主键，但我不明白为什么事务不起作用。这是我的环境（这是一个例子，不是真正的应用程序，但它会更容易解释）：

SGBD：MySql

数据库：emp、job、department（Oracle 示例）和 pkeys 用于生成主键

ORM：带有休眠的 JPA

企业应用：EmployeeJPA 有 2 个模块：EmployeeJPA-ejb 和 EmployeeJPA-war

EJB 实体：员工

@Entity
@Table(name = "employee")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Employee.findAll", query = "SELECT e FROM Employee e"),
    @NamedQuery(name = "Employee.findByEmployeeId", query = "SELECT e FROM Employee e WHERE e.employeeId = :employeeId"),
    @NamedQuery(name = "Employee.findByName", query = "SELECT e FROM Employee e WHERE e.name = :name"),
    @NamedQuery(name = "Employee.findByManagerId", query = "SELECT e FROM Employee e WHERE e.managerId = :managerId"),
    @NamedQuery(name = "Employee.findByHiredate", query = "SELECT e FROM Employee e WHERE e.hiredate = :hiredate"),
    @NamedQuery(name = "Employee.findBySalary", query = "SELECT e FROM Employee e WHERE e.salary = :salary")})
public class Employee implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @TableGenerator(name="EmployeePk", table="pkeys", pkColumnName="pkey_id",
            valueColumnName="pkey_val", pkColumnValue="EMPLOYEE", allocationSize=1)
    @GeneratedValue(strategy=GenerationType.TABLE, generator="EmployeePk")    
    @Basic(optional = false)
    @NotNull
    @Column(name = "employee_id")
    private Integer employeeId;
    . . .

EJB Session EmployeeFacade

@Stateless
@LocalBean
@TransactionManagement(TransactionManagementType.CONTAINER)
public class EmployeeFacade {
    @PersistenceContext(unitName = "EmployeesJPA-ejbPU")
    private EntityManager em;
    @EJB
    JobFacade jobFacade;
    @EJB
    DepartmentFacade departmentFacade;

    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public void addEmployee(String name, Date hiredate, double salary, int jobId, int departmentId, int managerId) throws Exception {
        Employee employee = new Employee();
        try{
            Department department = departmentFacade.getDepartmentById(departmentId);
            Job job = jobFacade.getJobById(jobId);
            employee.setDepartment(department);
            employee.setJob(job);
            employee.setHiredate(hiredate);
            employee.setManagerId(managerId);
            employee.setName(name);
            em.persist(employee);
        }catch(Exception ex){
            throw ex;
        }
    }
}

Servlet SrvlEmployee

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    String error = null;
    try {
        Date hiredate = Utilitaire.StrToDate("2020-02-01", "yyyy-MM-dd");
        employeeFacade.addEmployee("Smith", hiredate, 2000.00, 2, 3, 4);
    } catch (Exception e) {
        error = Utilitaire.getExceptionCause(e);
    } finally {
        request.setAttribute("errorR", error);
        RequestDispatcher dsp = request.getRequestDispatcher("/index.jsp");
        dsp.forward(request, response);
    }
}

之前的表 pkeys

插入员工之前的表格

之后的表 pkeys

插入员工后的表格

表employee的最后一个id是14

请求错误消息：

休眠：从部门department0_中选择department0_.department_id作为departmentme1_0_0_，department0_.dname作为dname2_0_0_，department0_.location作为location3_0_0_，其中department0_.department_id=？

休眠：从作业job0_中选择job0_.job_id作为job_id1_2_0_，job0_.jobname作为jobname2_2_0_，其中job0_.job_id=？

休眠：从 pkeys 中选择 pkey_val，其中 pkey_id = 'EMPLOYEE' 进行更新

休眠：更新 pkeys 设置 pkey_val = ? pkey_val = 哪里？和 pkey_id = 'EMPLOYEE'

Hibernate：插入员工（department_id，hiredate，job_id，manager_id，name，salary，employee_id）值（？，？，？，？，？，？，？）

SQL 错误：1062，SQL 状态：23000

键“P​​RIMARY”的重复条目“14”

似乎不仅有一笔交易，而且还有两笔交易，但我不明白为什么！我的错误在哪里？谢谢你的帮助 ！

标签： hibernatejpa

解决方案

推荐阅读