Hi guys, I am trying to understand the code below.
The point I am confused is why the code has relationship with origin?
SELECT *
FROM flights
WHERE origin in (
SELECT code
FROM airports
WHERE elevation > 2000);
for example, what I am understand is if the code in the airports table is changed to origin.
such as
SELECT *
FROM flights
WHERE origin in (
SELECT origin
FROM airports
WHERE elevation > 2000);