The documentation for "isolanguage" field on http://download.geonames.org/export/dump/ is:
iso 639 language code 2- or 3-characters; 4-characters 'post' for postal codes and 'iata','icao' and faac for airport codes, fr_1793 for French Revolution names, abbr for abbreviation, link for a website, varchar(7)
But you see that "isolanguage" column can be empty too:
3059101 2643743 en London City
3059102 2643743 en City of London
3059103 2643743 en The City 1
3173887 2643743 London
7581111 2643743 ext Londri
7581112 2643743 new लण्डन
7581113 2643743 mzn لندن
7581114 2643743 ilo Londres
7581115 2643743 tpi Landen
7581116 2643743 mwl Londres
In this case, it [i]looks[i] like when "isolanguage" is empty, then this alternate name is the official name. I would like to know more about this case: will *all* rows have a corresponding row that has isolanguage='' ?
My use case is that rather than filling a database table, I have a key/value store for each "isolanguage" (that matters). Currently my script has to query the database to get the name of the corresponding geoname_id, and use it as key, for the alternate name that is used as value.
If my script could expect every geoname in alternateNames to have a corresponding entry with isolanguage="", which contains what it would retrieve from the database: then i would not need to hit the database anymore (or rather, load it in memory ... yay !).
Thanks in advance for your support. (I hope this message makes sense !)