java - insert issue with auto-increment ID with Hibernate for a many to many association -

i use hibernate. db has many many relationship. hibernate generated these 2 classes handle relationship:

public class exducours implements java.io.serializable, iembededimproitem {      private static final long serialversionuid = 1017414l;     private exducoursid exducoursid;      private coursimpro coursimpro;     private eximpro eximpro; ...     @embeddedid      @attributeoverrides({ @attributeoverride(name = "coursid", column = @column(name = "cours_id", nullable = false) ),             @attributeoverride(name = "exid", column = @column(name = "ex_id", nullable = false) ),             @attributeoverride(name = "duree", column = @column(name = "duree") ),             @attributeoverride(name = "commentaire", column = @column(name = "commentaire") ),             @attributeoverride(name = "id", column = @column(name = "id", unique = true, nullable = false) )     }) 

and:

@embeddable public class exducoursid implements java.io.serializable {     private static final long serialversionuid = 10198474l;     private int coursid;     private int exid;     private integer duree=0;     private string commentaire;     private int id; id annotated way: @generatedvalue(strategy=generationtype.identity)     @column(name = "id", unique = true, nullable = false)     public int getid() {         return this.id;     } 

if try save instance, hibernate refuse because not recognize id field identity. can understand @attributeoverrides not specify @generatedvalue .

i did not find anyway set id identity value: @attributeoverride(name = "id", column = @column(name = "id", unique = true, nullable = false) ) if there way so, solution problem.

the alternate solution thought move id field class exducoursid exducours... made appropriate changes way:

public class exducours implements java.io.serializable, iembededimproitem { private static final long serialversionuid = 1017414l;     private exducoursid exducoursid;generated hibernate, contains parameters     private coursimpro coursimpro;     private eximpro eximpro;     private int id; //added id  field here!! 

i commented both lines: //@embeddedid // @attributeoverride(name = "id", column = @column(name = "id", unique = true, nullable = false) )

i removed references id in class exducoursid.

my demo stops fails error: error: insert statement conflicted foreign key constraint "fk_ex_du_cours_cours_impro". conflict occurred in database "improdb", table "dbo.cours_impro", column 'id'

can think solution? there must 1 setupping many many relationship via hibernate must extremely common.

thx in advance.