how to make a composite primary key (java persistence annotation)

Question

How to make it so that the table user_roles defines the two columns (userID, roleID) as a composite primary key. should be easy, just can\'t remember/find.

In

Answer 1

Composite keys are done using @IdClass (the other way is using @EmbeddedId and @Embeddable not sure which one you are looking for) the @IdClass is as follows

@Entity
@IdClass(CategoryPK.class)
public class Category {
    @Id
    protected String name;

    @Id
    protected Date createDate;

}

public class CategoryPK implements Serializable {

    String name;

    Date createDate;

    public boolean equals(object other) {
        //implement a equals that the PP can use to determine 
        //how the CategoryPK object can be identified.
    }

    public int hashCode(){
        return Super.hashCode();
    }
}

my Category here will be your user_roles and the name and createDate will be your userid and roleid