How to make the id created by spring boot in a many to many relation a primary key

Question

I have a many to many relation in my class but the problem is that the table created by spring boot contains and id which is not a primary key.
My code looks like:

 @JoinTable(name = "T_Commande_Produit",
            joinColumns = @JoinColumn(name = "idCommande"),
            inverseJoinColumns = @JoinColumn(name = "idProduit"))
    private List<Produit> products;
 

And the table created looks like this

+-------------+--------+------+-----+---------+-------+
| Field       | Type   | Null | Key | Default | Extra |
+-------------+--------+------+-----+---------+-------+
| id          | bigint | NO   | MUL | NULL    |       |
| id_commande | bigint | NO   | MUL | NULL    |       |
| id_produit  | bigint | NO   | MUL | NULL    |       |
+-------------+--------+------+-----+---------+-------+

Answer 1

If you are creating ManyToMany relation then you don't need a third ID variable you can simply set the primary key as id_commande and id_produit combination and you don't need a third entity in this case.

But if you still want to manually create a table that includes three fields that is the id, id_commande, and id_produit then you can create an Entity class That contains OneToMany Relation with others.

Code Example:
The third Entity is a table referencing both the Produit and Commande.

@Entity
class ThirdEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;

    @ManyToOne
    @JoinColumn(name = "id_commande")
    private Commande commande; 

    @ManyToOne
    @JoinColumn(name = "id_produit")
    private Produit produit;
}

Produit Entity

@Entity 
class ProduitEntity {
    // constructors and other fields excluded for simplicity.
    @OneToMany(mappedBy = "produit") // here produit is a object name of Produit in ThirdEntity
    private List<ThirdEntity> list;
}

Commande Entity

@Entity 
class CommandeEntity {
    // constructors and other fields excluded for simplicity
    @OneToMany(mappedBy = "commande") // here commande is a object name of Produit in ThirdEntity
    private List<ThirdEntity> list;
}