The entity class corresponding to the role table looks as follows:

@Entity
@Table(name="role",catalog="task_mgmt_system")
class Role {
    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    @Column(name = "id")
    private var id:Int? = null

    @Column(name="role")
    private var role : String? = null

    @ManyToMany(mappedBy = "roles",cascade = [CascadeType.PERSIST])
    private var users:Set<User>? = null
 // ... Getters and Setters
}

In the many-to-many relationship between User and Role entities, the ownership is with theUser entity so the @ManyToMany annotation in the Role entity is defined with the mappedBy attribute.