How to count the number of canceled flights from led airport that both departed and arrived on Thursday?

Question

PostgreSQL

There are two tables, routes and flights. It is necessary to count the number of canceled flights from Pulkovo Airport (LED), both departure and arrival of which were scheduled for Thursday.

Routes


Flights


This is a demo base from the postgres site: https://postgrespro.ru/education/demodb

Answer 1

Apparently:

SELECT COUNT(*) FROM Flights
WHERE status='Cancelled' AND ((departure_airport='LED' AND EXTRACT(DOW FROM TIMESTAMP sheduled_departure)=4)
OR (arrival_airport='LED' AND EXTRACT(DOW FROM TIMESTAMP sheduled_arrival)=4))