func (r *PayoutRepository) Payout(advertiserID, partnerID string, amount float32) error { advertiser, err := r.find(totalPayouts) // adicionar transação if err != nil { return err } partner, err := r.find(partnerID) if err != nil { return err } advertiser.Balance -= amount partner.Hold -= amount partner.Balance += amount if err := r.save(advertiser); err != nil { return err } if err := r.save(partner); err != nil { return err } r.totalPayouts++ return nil } func (r *PayoutRepository) find(id string) (Partner, error) { p := Partner{} err := r.db.QueryRow("SELECT * FROM partners WHERE id = " + id).Scan(&p) // adicionar $1 if err != nil { if err == sql.ErrNoRows { return p, errors.New("parceiro não encontrado") } return p, err } return p, nil }