Hibernate JPA，向多对多表添加数据时遇到问题

Question

I am creating a database and am having trouble getting the data to add to the many to many table connecting the operators to the routes they operate. All other data adds fine and I have absolutely no idea how to fix this.

Here's an extract from the console return, it shows that the operates table, the one I am failing to add too, has a different message

Hibernate: 
alter table operates 
    add index FKE22A276FF12BFD7F (number), 
    add constraint FKE22A276FF12BFD7F 
    foreign key (number) 
    references route (number)
Hibernate: 
alter table operates 
    add index FKE22A276FC0CF67CB (name), 
    add constraint FKE22A276FC0CF67CB 
    foreign key (name) 
    references operator (name)
Hibernate: 
insert 
into
    bus_stop
    (description, id) 
values
    (?, ?)
Hibernate: 
insert 
into
    bus_stop
    (description, id) 
values
    (?, ?)

Here's some of my code, have left out the get and set methods since they will be fine:

Route

@Entity
@NamedQueries({
    @NamedQuery(name = Route.SELECT_ALL, query = "select r from Route r 
order by r.number asc")
})
@Table(name = "route")
public class Route {
    @Id  @Column(name="number")
    private String number;

    private int frequency;
    private String start;
private String destination;

@ManyToMany(
        cascade = {CascadeType.PERSIST, CascadeType.MERGE},
        mappedBy = "routes",
        targetEntity = Operator.class)
private Set<Operator> operators = new HashSet<Operator>();

Operator

@Entity
@NamedQueries({
    @NamedQuery(name = Operator.SELECT_ALL, query = "select o from Operator 
 o order by o.name asc")
 })
 @Table(name = "operator")
 public class Operator {

@Id  @Column(name="name")
private String name;

private String street;
private String town;
private String postcode;
private String email;
private String phone;

@ManyToMany(
        targetEntity=Route.class,
        cascade={CascadeType.PERSIST, CascadeType.MERGE}
    )
    @JoinTable(
        name="operates",
        joinColumns=@JoinColumn(name="name"),
        inverseJoinColumns=@JoinColumn(name="number")
    )
private Set<Route> routes;

and the respective insert statements

    public static Session insert(final Map<String, String> row, Session session) {
    Operator o = new Operator();
    o.setRoutes(new HashSet<Route>());

    for (String key : row.keySet()) {
        if(key.equals("name"))
            o.setName(row.get(key));
        else if(key.equals("street"))
            o.setStreet(row.get(key));
        else if(key.equals("town"))
            o.setTown(row.get(key));
        else if(key.equals("postcode"))
            o.setPostcode(row.get(key));
        else if(key.equals("email"))
            o.setEmail(row.get(key));
        else if(key.equals("phone"))
            o.setPhone(row.get(key));
    }
    session.save(o);

    return session; 

public static Session insert(final Map<String, String> row, final Session session) {

        Route r = new Route();
        r.setOperators(new HashSet<Operator>());

        for (String key : row.keySet()) {
            if(key.equals("number"))
                r.setNumber(row.get(key));
            else if(key.equals("frequency"))
                r.setFrequency(Integer.parseInt(row.get(key)));
            else if(key.equals("start"))
                r.setStart(row.get(key));
            else if(key.equals("destination"))
                    r.setDestination(row.get(key));
            else if(key.equals("operators")){
                Set<String> operatorStrings = new HashSet<String>(Arrays.asList(row.get(key).split("|")));

                Operator o = new Operator();
                for(String s : operatorStrings){
                    o.setName(s);
                    r.getOperators().add(o);
                }
            }
        }

        session.save(r);

        return session;
    }

extra for comment

    Route r = new Route();
    r.setOperators(new HashSet<Operator>());

    for (String key : row.keySet()) {
        if(key.equals("number"))
            r.setNumber(row.get(key));
        else if(key.equals("frequency"))
            r.setFrequency(Integer.parseInt(row.get(key)));
        else if(key.equals("start"))
            r.setStart(row.get(key));
        else if(key.equals("destination"))
                r.setDestination(row.get(key));
        else if(key.equals("operators")){
            Set<String> operatorStrings = new HashSet<String>(Arrays.asList(row.get(key).split("|")));


            Operator o = new Operator();
            for(String s : operatorStrings){                    
                o.setName(s);
                o.setRoutes(new HashSet<Route>());
                o.getRoutes().add(r);
                r.getOperators().add(o);
            }
        }
    }

Answer 1

When adding Oerator or Route make sure that Route is in Operators.routes collection and operator is in Route.operators

In Route do:

public void addOperator(Operator o){
operators.add(o);
o.addRoute(this);
}

In Operator do:

public void addRoute(Route r){
routes.add(r);
r.addOperator(this);
}

And the same do when removing route or operator. This ensures that both sides of many-to-many relation are in sync.