Hibernate - Cascading problems using ManyToOne association

[Niklas Johansson]

Hello,

I am working with Hibernate trying to get ManyToOne working. But problems of course since I am here...

I am working with two classes (Tables)
1. Users
2. Incident

The users are unique and the identifier is "email". One user can have multiple incidents but one incident can only have one user. Though it is not a bi-directional relation, incident knows about the user but user doesn't know about the incident.

I am not getting any exceptions, the problem I am having is that only Incident table is updated and not the user table. Also, an extra column in the incident table is created named "USERS_EMAIL". I understand where I define this, but I didn't fully understand Hibernates instructions, perhaps handling it incorrect.

Shouldn't the cascading take care of updating my Users table automatically? Or do I have to explicitly persist my Users object? If that is the case, is there any point using @JoinColumn or at all defining the ManyToOne relation?

Any help would be most appreciated, especially as this seems to be the last big threshold for me applying Hibernate for real. Thanks in advance!

Show SQL:

Hibernate: insert into sessiondb.Incident (email, heading, mobile, name, users_email) values (?, ?, ?, ?, ?)

My Entity classes:

Users:

package sessionpackage;

import javax.persistence.*;

@Entity
public class Users {
	
	private String name = "";
	private String mobile = "";
	private String email = "";

	@Id
	public String getEmail(){
		return email; 		
	}
				
	public void setEmail(String email){
		this.email = email;	
	}
	
	public String getName(){
		return name;		
	}

	public String getMobile(){
		return mobile; 		
	}	
		
	public void setName(String name){
		this.name = name;	
	}

	public void setMobile(String mobile){
		this.mobile = mobile; 		
	}
}

And Incident

package sessionpackage;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;

@Entity
public class Incident {
	
	private Long id;
	private String name;
	private String email;
	private String mobile;
	private String heading;
	private Users usrs;
	
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	public Long getId(){
		return id;		
	}
	
	public void setId(Long id){
		this.id = id;
	}
	 
	@ManyToOne( cascade = {CascadeType.ALL}, targetEntity=Users.class)
	@JoinColumn(name="users_email")
	public Users getUsrs(){
		return usrs;
	}
	
	public void setUsrs(Users usrs){
		this.usrs = usrs;
	}
	
	public String getEmail(){
		return email;		
	}
	
	public void setEmail(String email){
		this.email = email;
	}
	
	public String getName(){
		return name;		
	}
	
	public void setName(String name){
		this.name = name;
	}
	
	public String getMobile(){
		return name;		
	}
	
	public void setMobile(String mobile){
		this.mobile = mobile;
	}
	
	public String getHeading(){
		return name;		
	}
	
	public void setHeading(String heading){
		this.heading = heading;
	}	
}

And from this class I am trying to save the data. The parameter data is coming in correctly, verified by System.out.println...

package sessionpackage;

import java.util.Map;

import org.hibernate.Session;
import org.hibernate.Transaction;

public class IncidentDBHandler {
	
	public void registerUser(Map<String, String[]> parameters){
		
		Session session = HibernateUtil.getSessionFactory().openSession();		
		Transaction tx = session.beginTransaction();
		Incident inc = new Incident();
		
		inc.setHeading(parameters.get("heading")[0]);		
		inc.setMobile(parameters.get("mobile")[0]);		
		inc.setName(parameters.get("name")[0]);		
		inc.setEmail(parameters.get("email")[0]);
		
		Long msgId = (Long) session.save(inc);		
		tx.commit();				
		session.close();					
		HibernateUtil.shutdown();			
	}	
}

Best Regards,
Niklas

[Mark Spritzler]

We have an ORM forum for Hibernate questions.

Moving this to that forum

Mark