BAD_Analytics/SQL files/8.sql
2019-05-13 20:08:00 +02:00

43 lines
1.1 KiB
Transact-SQL

--Average delays between 1 and 23 per carrier
DECLARE @1_23avg TABLE
(
carrier VARCHAR(50),
avg FLOAT
)
INSERT INTO @1_23avg
SELECT carrier,
AVG(avg1) AS 'avg1A'
FROM (SELECT carrier,
AVG(arr_delay) AS 'avg1'
FROM Flight_delays
WHERE month = 7
GROUP BY carrier, day_of_month
HAVING day_of_month BETWEEN 1 AND 23) AS T1
GROUP BY carrier;
--Average delays between 24 and 31 per carrier
DECLARE @24_31avg TABLE
(
carrier VARCHAR(50),
avg FLOAT
)
INSERT INTO @24_31avg
SELECT carrier,
AVG(avg2) AS 'avg2A'
FROM (SELECT carrier,
AVG(arr_delay) AS 'avg2'
FROM Flight_delays
WHERE month = 7
GROUP BY carrier, day_of_month
HAVING day_of_month BETWEEN 24 AND 31) AS T2
GROUP BY carrier;
--Final SELECT
SELECT T1.carrier AS 'Carrier',
T1.avg-T2.avg AS 'Delay growth'
FROM @1_23avg T1 INNER JOIN @24_31avg T2
ON T1.carrier = T2.carrier
ORDER BY T1.avg-T2.avg DESC;