One-to-Many query for collection

Question

I have a One-to-Many relation:

public class Account{
  @OneToMany(cascade=CascadeType.ALL)
  private List<Transaction>transactions = new ArrayList<>();
}

public class Transaction{
    @ManyToOne
    @JoinColumn(name="ACCOUNT_ID")
    private Account account;
}

I want to get all Accounts for a User , and it works, but Transaction list is empty. Is this a matter of entity mapping or should I modify my query?

I started with (empty transaction list):

TypedQuery<Account>query  = em.createQuery("SELECT a FROM Account a WHERE a.user.id = ?1",Account.class);

also tried to join like so (no accounts returned at all):

 TypedQuery<Account>query  = em.createQuery("SELECT a FROM Account a JOIN a.transactions t WHERE a.user.id = ?1",Account.class);

What's wrong here?

Answer 1

It seems you forgot to add mappedBy in the annotation properties:

@OneToMany(cascade=CascadeType.ALL, mappedBy="account")
private List<Transaction>transactions = new ArrayList<>();