Develop an ERM and EERM for the following case study. Include:
Entities (incluing names),
Relationships (including names),
minimum and maximum cardinalities,
intersection entities, and
primary and foreign keys.
CASE
An airline has multiple planes
Each plane goes on multiple flights
Each flight is on a route
Routes connect two (served) cities
Each flight is staffed by 2 pilots
Each flight is staffed by one or no air marshalls
Each flight has one or more members of a cabin crew
Passengers purchase one or more tickets for flights
Tickets are for one flight. (A flight with one stop is two flights)