Question

我有三张桌子

员工：存储员工信息
role_description：存储我喜欢的角色类型管理员，区域经理，国家/地区经理
employee_role_details：员工和角色描述与一些额外字段之间存在多对多的关系。

现在我在从employee_role_details中获取来自employee表的（employee_id，email），（role_ownership，role_id）的结果以及来自role_description中与role_id相对应的role_description的（role_name和role_description）时遇到问题。

Employee.java

@Entity
@Table(name = "employee", uniqueConstraints= @UniqueConstraint(columnNames={"employee_email"}))
public class Employee {

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

    @Column(name = "employee_name")
    private String employeeName;

    @Column(name = "employee_email", unique = true, nullable = false)
    private String employeeEmail;

    @Column(name = "contact_no")
    private String contactNo;

    @Column(name = "password")
    private String password;

    @Column(name = "is_active")
    private Boolean isActive = true;

    @Transient
    private long EmployeeRoleId;

    @Transient
    private String roleName;

    @Transient
    private int totalpage;

    @OneToMany(mappedBy = "employee", cascade = CascadeType.ALL)
    //@JsonIgnore
    @JsonManagedReference(value = "employeeRoleRecord-employee")
    @LazyCollection(LazyCollectionOption.FALSE)
    private List<EmployeeRoleRecord> roleRecords = new ArrayList<>();

    @OneToMany(mappedBy = "assignedTo", cascade = CascadeType.ALL)
    @JsonManagedReference(value = "complaint-treatment-employee")
    @LazyCollection(LazyCollectionOption.FALSE)
    private List<ComplaintsCategory> complaintCategoryAssignedTo = new ArrayList<>();

EmployeeDescription.java

@Entity
@Table(name = "role_description")
public class RoleDescription {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "role_id")
    private long roleId;

    @Column(name = "role_name")
    private String roleName;

    @Column(name = "role_description")
    private String roleDescription;

    @Column(name = "status")
    private boolean status;

    @OneToMany(mappedBy = "description", cascade = CascadeType.ALL)
    @JsonManagedReference(value = "employeeRoleRecord-roleDescription")
    @LazyCollection(LazyCollectionOption.FALSE)
    private List<EmployeeRoleRecord> roleRecords = new ArrayList<EmployeeRoleRecord>();

EmployeeRoleRecord

@Entity
@Table(name = "employee_role_record")
public class EmployeeRoleRecord {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "employee_role_id")
    private long employeeRoleId;

    @Column(name = "role_ownership")
    private String roleOwnership;

    @Column(name = "status")
    private boolean status = true;


    @ManyToOne(cascade=CascadeType.ALL)
    @JsonBackReference(value = "employeeRoleRecord-employee")
    @JoinColumn(name = "employee_id")
    private Employee employee;

    @ManyToOne(cascade=CascadeType.ALL)
    @JsonBackReference(value = "employeeRoleRecord-roleDescription")
    @JoinColumn(name = "role_id")
    private RoleDescription description;

    @Transient
    private long roleId;

dao中的代码

public Employee getEmployeeByEmail(String email) {
        return (Employee) sessionFactory.getCurrentSession()
                .createCriteria(Employee.class)
                .add(Restrictions.eq("employeeEmail", email)).uniqueResult();
    }

服务：

public Employee getSurveyData(String employeeEmail){

        Employee loggedInEmployee =
                 loginDao.getEmployeeByEmail(employeeEmail);

        Employee  loggedInEmployeeRecord = new Employee();

            loggedInEmployeeRecord.setEmployeeId(loggedInEmployee.getEmployeeId());
            loggedInEmployeeRecord.setEmployeeName(loggedInEmployee.getEmployeeName());

            List<EmployeeRoleRecord> employeeRoleRecords = loggedInEmployee.getRoleRecords();

            List<EmployeeRoleRecord> employeeRoleRecord = new  ArrayList<>();

            for(EmployeeRoleRecord record :  employeeRoleRecords){

                EmployeeRoleRecord employeeRole = new EmployeeRoleRecord();

                employeeRole.setRoleId(record.getDescription().getRoleId());
                employeeRole.setRoleName(record.getDescription().getRoleName());
                employeeRole.setRoleOwnership(record.getRoleOwnership());
                employeeRole.setStatus(record.isStatus());
                employeeRoleRecord.add(employeeRole);
            }

            loggedInEmployeeRecord.setRoleRecords(employeeRoleRecord);


         return loggedInEmployee;
    }

输出：

    {
  "employeeId": 1,
  "employeeName": "Dhyanandra Singh",
  "employeeEmail": "admin",
  "contactNo": "9893651872",
  "password": "123456",
  "isActive": true,
  "roleRecords": [
    {
      "employeeRoleId": 1,
      "roleOwnership": "overall project",
      "status": true,
      "roleId": 0,
      "roleName": null
    }
  ],
}

问题：

json输出我在角色记录列表中没有包含角色ID和角色名称。

Answer 1

问题是：

EmployeeRoleRecord classe上的roleId属性被映射为@Transient，这意味着它不会持久存储在数据库中，因此Hibernate无法获取此字段的结果。

看看你的课程建模我无法弄清楚你想要用roleId确切绘制什么，我建议采用两种可能的方法：

不要直接在getEmployeeByEmail方法上返回您的查询。首先得到结果，然后迭代它并在每条记录上手动设置所需的roleId;
检查您的模型方案并为roleId制作正确的映射，它可能应该引用另一个实体，因此请确保正确映射关系以在单个查询中获取结果。

Answer 2

在EmployeeRoleRecord中添加了临时roleId和roleName，然后在服务中进行了一些修改。比如迭代列表设置roleId和roleName。

public Employee getSurveyData(String employeeEmail){

            Employee loggedInEmployee =
                     loginDao.getEmployeeByEmail(employeeEmail);

            Employee  loggedInEmployeeRecord = new Employee();

                loggedInEmployeeRecord.setEmployeeId(loggedInEmployee.getEmployeeId());
                loggedInEmployeeRecord.setEmployeeName(loggedInEmployee.getEmployeeName());
                loggedInEmployeeRecord.setEmployeeEmail(loggedInEmployee.getEmployeeEmail());
                loggedInEmployeeRecord.setContactNo(loggedInEmployee.getContactNo());

                List<EmployeeRoleRecord> employeeRoleRecords = loggedInEmployee.getRoleRecords();

                List<EmployeeRoleRecord> employeeRoleRecord = new  ArrayList<>();

                for(EmployeeRoleRecord record :  employeeRoleRecords){

                    EmployeeRoleRecord employeeRole = new EmployeeRoleRecord();

                    employeeRole.setEmployeeRoleId(employeeRole.getEmployeeRoleId());
                    employeeRole.setRoleId(record.getDescription().getRoleId());
                    employeeRole.setRoleName(record.getDescription().getRoleName());
                    employeeRole.setRoleOwnership(record.getRoleOwnership());
                    employeeRole.setStatus(record.isStatus());
                    employeeRoleRecord.add(employeeRole);
                }

                loggedInEmployeeRecord.setRoleRecords(employeeRoleRecord);


             return loggedInEmployeeRecord;
        }

在多对多关系的情况下获取结果

2 个答案: