CREATE TABLE airports (
    gid SERIAL NOT NULL PRIMARY KEY,
    name TEXT,
    city TEXT,
    country TEXT,
    iata TEXT,
    icao TEXT,
    geom GEOMETRY,
    latitude DOUBLE PRECISION,
    longitude DOUBLE PRECISION,
    altitude DOUBLE PRECISION,
    CONSTRAINT enforce_dims_geom CHECK (st_ndims(geom) = 2),
    CONSTRAINT enforce_geotype_geom CHECK (geometrytype(geom) = 'POINT'::text OR geom IS NULL),
    CONSTRAINT enforce_srid_geom CHECK (st_srid(geom) = 4326)
);