SELECT COUNT(*) FROM airlines
How many airlines are there?
CREATE TABLE routes (
    rid number,
    dst_apid number,
    dst_ap text,
    src_apid number,
    src_ap text,
    alid number,
    airline text,
    codeshare text
)

CREATE TABLE airlines (
    alid number,
    name text,
    iata text,
    icao text,
    callsign text,
    country text,
    active text
)

CREATE TABLE airports (
    apid number,
    name text,
    city text,
    country text,
    x number,
    y number,
    elevation number,
    iata text,
    icao text
)