Mapping calculated properties with JPA

Question

Is there a way to map a calculated property using JPA?

Assuming I have an Invoice object with one or more InvoiceLineItems within it, I wan

Answer 1

Perhaps the PrePersist annotation can be used for this.

@Column(name = "TOTAL_AMOUNT")
private BigDecimal totalAmount;

@PrePersist
public void updateTotalAmount() {
    BigDecimal amount = BigDecimal.ZERO;
    for (InvoiceLineItem lineItem : lineItems) {
        amount = amount.add(lineItem.getTotalAmount());
    }
    this.totalAmount = amount;
}