How to Work with Composite Primary Key

Question

Hi All,
I'm working with Toplink JPA. Here I have A problem with inserting into database table which have composite Primary Key.
What I'm doing is, I have two tables. to maintain many to many relation between these two tables I created another intermediate table which consists of foreign Keys (reference) of above two tables.
Now these two foreign Keys in the Intermediate table made as composite Primary Keys.
When I'm trying to the data in the Intermediate table I'm getting the foreign Keys values are null..
could anyone suggest me how to work with composite Primary Keys
Thanks,
Satish

Answer 1

I have the same problem, I have 3 tables with a join table joining them all. I have created an intermediate table entity. When I go to create a an entry, it says that I cannot enter null into "ID". Here is the SQl toplink generates:
INSERT INTO Z_AUTH_USER_AUTHORIZATION (CONTEXT_ID, AUTHORIZATION_ID, USER_ID) VALUES (?, ?, ?)
bind => [null, null, null]
Here are the classes:
-----------------------Join Table-----------------------------------------------
@Entity()
@Table(name = "Z_AUTH_USER_AUTHORIZATION")
public class AuthUserAuthorization implements Serializable{
@EmbeddedId
private AuthUserAuthorizationPK compId;
// bi-directional many-to-one association to AuthAuthorization
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "AUTHORIZATION_ID", referencedColumnName = "ID", nullable = false, insertable = false, updatable = false)
private AuthAuthorization authAuthorization;
// bi-directional many-to-one association to AuthContext
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "CONTEXT_ID", referencedColumnName = "ID", nullable = false, insertable = false, updatable = false)
private AuthContext authContext;
// bi-directional many-to-one association to AuthUser
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "USER_ID", referencedColumnName = "ID", nullable = false, insertable = false, updatable = false)
private AuthUser authUser;
---------------------------------------User table--------------------------------------------------------------
@Entity()
@Table(name = "Z_AUTH_USER")
public class AuthUser implements Serializable, IUser{
@Id()
@SequenceGenerator(name = "AUTH_USER_ID_SEQ", sequenceName = "Z_AUTH_USER_ID_SEQ")
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "AUTH_USER_ID_SEQ")
@Column(name = "ID", unique = true, nullable = false, precision = 10)
private Integer id;
// bi-directional many-to-one association to AuthUserAuthorization
@OneToMany(mappedBy = "authUser", fetch = FetchType.EAGER)
private java.util.Set<AuthUserAuthorization> authUserAuthorizations;
-----------------------------------Context table-----------------------------------------------------------------
@Entity()
@Table(name = "Z_AUTH_CONTEXT")
public class AuthContext implements Serializable, IContext{
@Id()
@SequenceGenerator(name = "AUTH_CONTEXT_ID_SEQ", sequenceName = "Z_AUTH_CONTEXT_ID_SEQ")
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "AUTH_CONTEXT_ID_SEQ")
@Column(name = "ID", unique = true, nullable = false, precision = 8)
private Integer id;
// bi-directional many-to-one association to AuthUserAuthorization
@OneToMany(mappedBy = "authContext", fetch = FetchType.EAGER)
private java.util.Set<AuthUserAuthorization> authUserAuthorizations;
----------------------------Authorization table-------------------------------------------------
@Entity()
@Table(name = "Z_AUTH_AUTHORIZATION")
public class AuthAuthorization implements Serializable, IAuthorization{
@Id()
@SequenceGenerator(name = "AUTH_AUTHORIZATION_ID_SEQ", sequenceName = "Z_AUTH_AUTHORIZATION_ID_SEQ")
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "AUTH_AUTHORIZATION_ID_SEQ")
@Column(name = "ID", unique = true, nullable = false, precision = 8)
private Integer id;
// bi-directional many-to-one association to AuthUserAuthorization
@OneToMany(mappedBy = "authAuthorization", fetch = FetchType.EAGER)
private java.util.Set<AuthUserAuthorization> authUserAuthorizations;
I have tried to create the new entity several ways. I have tried to create one with the default constructor then set this entity on each of the other entities, I have also tried to pass in the entities to the join entity and set them there, but this doesn't work. Any help would be very appreciated!
Thanks,
Bill