@Entity
@Table(uniqueConstraints
        = @UniqueConstraint(columnNames = {"menuName"}))
public class Menu implements Serializable, Comparable<Menu> {

    @Id
    @SequenceGenerator(name = "menu_sq", initialValue = 3, allocationSize = 1)
    @GeneratedValue(generator = "menu_sq")
    private Long menu_id;
    private String menuName;
    private Boolean activeStatus = true;
    @OneToMany(cascade = {CascadeType.PERSIST,CascadeType.REMOVE}, mappedBy = "menu")
    @PrivateOwned
    private List<MenuItem> menuItems = new ArrayList<>();

    //setters getters
}

@Entity
@Table(uniqueConstraints
        = @UniqueConstraint(columnNames = {"menuItem","menu_id"}))
public class MenuItem implements Serializable, Comparable<MenuItem> {

    @Id
    @SequenceGenerator(name = "menuItem_sq", initialValue = 10, allocationSize = 1)
    @GeneratedValue(generator = "menuItem_sq", strategy = GenerationType.SEQUENCE)
    private Long menuItem_id;
    private String menuItem;
    private Short line_num;
    private Long view_id;
    @ManyToOne
    @JoinColumn(name = "MENU_ID")
    private Menu menu;

//setters getters
}