HQL query for the unary table - sql

Question

I have an user_info table as below
As you see the supervisor column refers the same table.
I am using the Netbean for my development. My POJO created the following class
package database.hibernate_pojo;
// Generated May 31, 2013 12:50:13 AM by Hibernate Tools 3.2.1.GA
import java.util.HashSet;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
/**
* UserInfo generated by hbm2java
*/
#Entity
#Table(name="user_info"
,catalog="bit_final_year_project"
, uniqueConstraints = #UniqueConstraint(columnNames="user_name")
)
public class UserInfo implements java.io.Serializable {
private Integer userId;
private UserInfo userInfo;
private String userName;
private String firstName;
private String secondName;
private char department;
private String password;
private char privilege;
private int invalidLogin;
private char status;
private String signaturePath;
private Set<Shipping> shippings = new HashSet<Shipping>(0);
private Set<Audit> audits = new HashSet<Audit>(0);
private Set<UserInfo> userInfos = new HashSet<UserInfo>(0);
public UserInfo() {
}
public UserInfo(String userName, String firstName, String secondName, char department, String password, char privilege, int invalidLogin, char status) {
this.userName = userName;
this.firstName = firstName;
this.secondName = secondName;
this.department = department;
this.password = password;
this.privilege = privilege;
this.invalidLogin = invalidLogin;
this.status = status;
}
public UserInfo(UserInfo userInfo, String userName, String firstName, String secondName, char department, String password, char privilege, int invalidLogin, char status, String signaturePath, Set<Shipping> shippings, Set<Audit> audits, Set<UserInfo> userInfos) {
this.userInfo = userInfo;
this.userName = userName;
this.firstName = firstName;
this.secondName = secondName;
this.department = department;
this.password = password;
this.privilege = privilege;
this.invalidLogin = invalidLogin;
this.status = status;
this.signaturePath = signaturePath;
this.shippings = shippings;
this.audits = audits;
this.userInfos = userInfos;
}
#Id #GeneratedValue(strategy=IDENTITY)
#Column(name="user_id", unique=true, nullable=false)
public Integer getUserId() {
return this.userId;
}
public void setUserId(Integer userId) {
this.userId = userId;
}
#ManyToOne(fetch=FetchType.LAZY)
#JoinColumn(name="supervisor")
public UserInfo getUserInfo() {
return this.userInfo;
}
public void setUserInfo(UserInfo userInfo) {
this.userInfo = userInfo;
}
#Column(name="user_name", unique=true, nullable=false, length=12)
public String getUserName() {
return this.userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
#Column(name="first_name", nullable=false, length=15)
public String getFirstName() {
return this.firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
#Column(name="second_name", nullable=false, length=15)
public String getSecondName() {
return this.secondName;
}
public void setSecondName(String secondName) {
this.secondName = secondName;
}
#Column(name="department", nullable=false, length=1)
public char getDepartment() {
return this.department;
}
public void setDepartment(char department) {
this.department = department;
}
#Column(name="password", nullable=false, length=45)
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
#Column(name="privilege", nullable=false, length=1)
public char getPrivilege() {
return this.privilege;
}
public void setPrivilege(char privilege) {
this.privilege = privilege;
}
#Column(name="invalid_login", nullable=false)
public int getInvalidLogin() {
return this.invalidLogin;
}
public void setInvalidLogin(int invalidLogin) {
this.invalidLogin = invalidLogin;
}
#Column(name="status", nullable=false, length=1)
public char getStatus() {
return this.status;
}
public void setStatus(char status) {
this.status = status;
}
#Column(name="signature_path", length=45)
public String getSignaturePath() {
return this.signaturePath;
}
public void setSignaturePath(String signaturePath) {
this.signaturePath = signaturePath;
}
#OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="userInfo")
public Set<Shipping> getShippings() {
return this.shippings;
}
public void setShippings(Set<Shipping> shippings) {
this.shippings = shippings;
}
#OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="userInfo")
public Set<Audit> getAudits() {
return this.audits;
}
public void setAudits(Set<Audit> audits) {
this.audits = audits;
}
#OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="userInfo")
public Set<UserInfo> getUserInfos() {
return this.userInfos;
}
public void setUserInfos(Set<UserInfo> userInfos) {
this.userInfos = userInfos;
}
}
I want to show the name of the supervisor in my application. I have written the SQL command it worked perfectly in the Workbench.
select e.user_name from user_info e, user_info s where e.user_id=s.supervisor
But the issue was when I tried to write it in HQL there is no respective methods were created by the Netbean in UserInfo class.
Can anyone help me out of this issue to find a solution?

Answer 1

I've found the solution for my issue by my own. It's simply object within another object. Thus I need to query the first object, then the second object can be accessed
public Iterator getCustomSupervisor(){
String hqlQuery = "FROM UserInfo";
Query query = session.createQuery(hqlQuery);
while(query.list().iterator().hasNext()){
//the first object
UserInfo ui = (UserInfo) query.list().iterator().next();
//access the second object
System.out.println(ui.getUserInfo().getUserName());
}
}