func createOrder()

in orders.go [94:142]
46 lines of code
11 McCabe index (conditional complexity)

func createOrder(ctx context.Context, db *sqlx.DB, customer *Customer, lines []ProductOrderLine) (int, error) {
	tx, err := db.BeginTxx(ctx, nil)
	if err != nil {
		return -1, err
	}
	defer tx.Rollback()

	driver := db.DriverName()
	returningID := "RETURNING id"
	if driver == "sqlite3" {
		returningID = ""
	}
	insertOrderStmt := db.Rebind("INSERT INTO orders (customer_id) VALUES (?) " + returningID)

	insertOrderLineStmt, err := tx.PrepareContext(ctx, db.Rebind(
		"INSERT INTO order_lines (order_id, product_id, amount) VALUES(?, ?, ?)",
	))
	if err != nil {
		return -1, errors.Wrap(err, "failed to prepare insert order lines statement")
	}
	defer insertOrderLineStmt.Close()

	var orderID int
	if returningID == "" {
		result, err := tx.ExecContext(ctx, insertOrderStmt, customer.ID)
		if err != nil {
			return -1, err
		}
		rowID, err := result.LastInsertId()
		if err != nil {
			return -1, err
		}
		orderID = int(rowID)
	} else {
		err := tx.QueryRowContext(ctx, insertOrderStmt, customer.ID).Scan(&orderID)
		if err != nil {
			return -1, err
		}
	}
	for _, line := range lines {
		if _, err := insertOrderLineStmt.ExecContext(ctx, orderID, line.Product.ID, line.Amount); err != nil {
			return -1, err
		}
	}
	if err := tx.Commit(); err != nil {
		return -1, err
	}
	return orderID, nil
}