CREATE TABLE IF NOT EXISTS metars ( id INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY, raw_text TEXT NOT NULL, station_id TEXT NOT NULL, observation_time TEXT NOT NULL, latitude DOUBLE PRECISION NOT NULL, longitude DOUBLE PRECISION NOT NULL, temp_c DOUBLE PRECISION, dewpoint_c DOUBLE PRECISION, wind_dir_degrees TEXT, wind_speed_kt INTEGER, visibility_statute_mi TEXT, altim_in_hg DOUBLE PRECISION, sea_level_pressure_mb DOUBLE PRECISION, wx_string TEXT, flight_category TEXT, three_hr_pressure_tendency_mb DOUBLE PRECISION, metar_type TEXT NOT NULL, max_t_c DOUBLE PRECISION, min_t_c DOUBLE PRECISION, precip_in DOUBLE PRECISION, elevation_m INTEGER NOT NULL );