entity BankAccount {
  name String required,
  balance BigDecimal required
}
entity Label {
  label String required minlength(3)
}
entity Operation {
  date ZonedDateTime required,
  description String,
  amount BigDecimal required
}
relationship OneToMany {
  BankAccount{operation} to Operation{bankAccount(name)}
}
relationship ManyToOne {
  BankAccount{user(login)} to User
}
relationship ManyToMany {
  Operation{label(label)} to Label{operation}
}