我有三个表
employee:存储员工信息
role_description:存储我拥有的角色类型,例如管理员、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关系。
现在,我在从员工表中获取包含 (employee_id, email),从 employee_role_details 中获取包含 (role_ownership, role_id) 以及从与 role_description 中的 role_id 对应的 role_description 中获取(role_name 和 role_description)的结果时遇到问题。
员工.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<>();
员工描述.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>();
员工角色记录
@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:
我得到的 json 输出在角色记录列表中不包含角色 ID 和角色名称。
最佳答案
问题是:
您在 EmployeeRoleRecord 类上的 roleId 属性映射为@Transient,这意味着它不会持久保存在数据库中,因此 Hibernate 无法获取该字段的结果。
查看您的类建模,我无法弄清楚您试图用 roleId 映射什么,我建议两种可能的方法:
不要直接返回您对 getEmployeeByEmail 方法的查询。首先获取结果,然后迭代它并在每条记录上手动设置您想要的所需 roleId;
检查您的模型方案并为 roleId 进行正确的映射,它可能应该引用另一个实体,因此请确保正确映射关系以便在单个查询中获得结果。
祝你好运。
关于java - 在多对多关系的情况下获取结果,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33970508/