= wikidata =
Wikidata is a free and open knowledge base that can be read and edited by both humans and machines.

Wikidata acts as central storage for the structured data of its Wikimedia sister projects including Wikipedia, Wikivoyage, Wiktionary, Wikisource, and others. 

 * https://www.wikidata.org/wiki/Wikidata:List_of_properties/science
 * https://www.wikidata.org/wiki/Q597

== Query ICAO codes ==
 * https://query.wikidata.org/#SELECT%20%3Fitem%20%3FitemLabel%20%3Fid%20WHERE%20%7B%0A%20%20%3Fitem%20wdt%3AP239%20%3Fid%0A%20%20SERVICE%20wikibase%3Alabel%20%7B%20bd%3AserviceParam%20wikibase%3Alanguage%20%22%5BAUTO_LANGUAGE%5D%2Cen%22.%20%7D%0A%7D
 * https://www.wikidata.org/wiki/Property:P239
{{{
SELECT ?item ?itemLabel ?id WHERE {
  ?item wdt:P239 ?id
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}
}}}

{{{
SELECT DISTINCT ?id WHERE {
  ?item wdt:P239 ?id
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
} ORDER BY ?id 
}}}

== Query IATA codes ==
 * https://www.wikidata.org/wiki/Property:P238
{{{
SELECT ?item ?itemLabel ?id WHERE {
  ?item wdt:P238 ?id
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}
}}}

{{{
SELECT DISTINCT ?id WHERE {
  ?item wdt:P238 ?id
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
} ORDER BY ?id 
}}}

== Get items that are instances of cities of Portugal ==
 * https://www.wikidata.org/wiki/Property:P31
 * https://www.wikidata.org/wiki/Q15647906
{{{
SELECT ?item ?itemLabel WHERE {
  ?item wdt:P31 wd:Q15647906
  SERVICE wikibase:label { bd:serviceParam wikibase:language "pt". }
}
}}}

== Get Portugal cities and their freguesias ==
 * https://www.wikidata.org/wiki/Property:P150  contains administrative territorial entity (P150) 
 * https://www.wikidata.org/wiki/Property:P31   instance of (P31) 
 * https://www.wikidata.org/wiki/Q15647906   city of Portugal (Q15647906) 
 * https://www.wikidata.org/wiki/Q1131296 freguesia
{{{
SELECT ?item ?itemLabel ?itemDescription ?freguesia ?freguesiaLabel WHERE {
  ?item wdt:P31 wd:Q15647906 . ?item wdt:P150 ?freguesia.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "pt". }
}
}}}