4 курс 1 семестр / Курсовая / SQL / PR10

DELIMITER $$
CREATE PROCEDURE pr10(IN airline_name VARCHAR(255))
BEGIN
DECLARE result INT;
SELECT COUNT(flights.flight_id) INTO result
FROM flights
JOIN airlines ON flights.airline_code = airlines.airline_code
WHERE flights.dep_time > flights.time AND airlines.name=airline_name;

IF result=0 THEN
SELECT 'Задержанных рейсов для этой авиакомпании не найдено' AS 'Error';
ELSE
SELECT airlines.name, COUNT(flights.flight_id) as delayedflights
FROM flights
JOIN airlines ON flights.airline_code = airlines.airline_code
WHERE flights.dep_time > flights.time AND airlines.name = airline_name
GROUP BY airlines.name;
END IF;
END $$
DELIMITER ;

CALL pr10('Test');

DROP PROCEDURE pr10;