Verify aviation recipe and whether FLIGHT_ID needs to be projected because it is used in the INNER JOIN

[ybyzek]

Porting confluentinc/ksqldb-recipes#149 here

From @wicknicks

just a quick pointer: was going through this https://confluentinc.github.io/ksqldb-recipes/customer-360/aviation/#ksqldb-code, and noticed that the CREATE STREAM customer_flight_updates ... statement must also project a FLIGHT_ID column too? it’d be an error otherwise?

yes, I got an error (but I was using some internal ksqldb libs when working with this recipe though). so you might want to take a run too, in case I had something wrong with my setup.