Confused with many to many,

[Diego Gusava]

Hi,

i have a database with 2 tables ...

Table User
 id_user PK
 name_user 

Table UserManager
 id_user_manager FK (User)
 id_user FK(User)

where User Manager can have one or more user above.
how i can resolve this problem, im confused ...

public class User {

	private Integer id;
	private String name;
	private List<User> listUser;
}

[Sean Clark]

Hey,

Firstly you don't seem to have a primary key on the UserManager table, not really a problem but you may want to add in a surrogate primary key.

Secondly I'm not sure what your question is, have you made any ORM mappings? Your user model looks ok, but remember that each User will have 2 lists, 1 will be the list of managers (users) that a user has and the other will be a list of employees (users) that the user manages each of these will map to a different column in the UserManager table.

Sean

[Diego Gusava]

@Entity
@Table(name = "USER")
public class User {
	
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	@Column(name="ID")
	private Integer id;
	
	@Column(name="NAME")
	private String name;
	
	@ManyToMany
	@JoinTable(name="UserManager",
		joinColumns=@JoinColumn(name="id_user_manager"),
		inverseJoinColumns=@JoinColumn(name="id_user")
	)
	private List<User> listUserEmployee;
	
	@ManyToMany
	@JoinTable(name="UserManager",
		joinColumns=@JoinColumn(name="id_user"),
		inverseJoinColumns=@JoinColumn(name="id_user_manager")
	)
	private List<User> listUserManager;
	

}

Sean Clark like this?

[Sean Clark]

Hey,

Yeah that looks ok to me... so what problem are you having?

Sean

[Diego Gusava]

Thanks Sean Clark! i was confused only. Its correct now.