休眠级联保存

Question

I have a problem with Hibernate. See my data model

I have class - "Ticket"...

@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(name = "ticketComposition",
        joinColumns = { @JoinColumn(name = "ticketId")},
        inverseJoinColumns = { @JoinColumn(name = "tripsSiteId")})
private Set<TripsSite> tripsSites = new HashSet<TripsSite>();

and when I'm trying to save new ticket...

    Ticket ticket = new Ticket();
    User user = userService.findBySSO(userName);
    ticket.setUser(user);


    ticket.setTripsSites(new HashSet<>(tripsSites));

    persist(ticket);

I get the following error: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails ( sbb . ticketcomposition , CONSTRAINT ticket FOREIGN KEY ( ticketId ) REFERENCES ticket ( id ))

How can i resolve this problem?

Answer 1

Assuming you have something like this defined on the TicketSite entity:

@ManyToMany(mappedBy="tripSites")
private Set<Trip> trips = new HashSet<Trip>();

While persisting, you have to set the dependencies on both sides of the @ManyToMany mapping:

Ticket ticket = new Ticket();
User user = userService.findBySSO(userName);
ticket.setUser(user);

ticket.setTripsSites(new HashSet<>(tripsSites));

for(TicketSite ticketSite: ticketSites){
   ticketSite.getTickets().add(ticket);
} 

persist(ticket);

I am assuming that the ticketSites set has been previously retrieved from the database and has been persisted before this transactional method started.