User:JakobVoss/Identifiers

identifier items edit

SELECT ?id ?idLabel ?idDescription 
?instanceOfLabel ?subclassOfLabel
?country ?jurisdiction ?issuedBy ?operator ?regex 
?urlTemplate
?property
WHERE { 
  ?id wdt:P279* wd:Q6545185 
  OPTIONAL { ?id wdt:P31 ?instanceOf }
  OPTIONAL { ?id wdt:P279 ?subclassOf } 
  OPTIONAL { ?id wdt:P17 ?country }
  OPTIONAL { ?id wdt:P1001 ?jurisdiction }
  OPTIONAL { ?id wdt:P2378 ?issuedBy }
  OPTIONAL { ?id wdt:P137 ?operator }
  OPTIONAL { ?id wdt:P1793 ?regex }
  OPTIONAL { ?id wdt:P1630 ?urlTemplate }
  OPTIONAL { ?id wdt:P1687 ?property }  
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}

Try it!

Properties of individual identifier system items:

format as a regular expression (P1793) and
country (P17)
...

identifier items and properties edit

Wikidata property (P1687) and Wikidata item of this property (P1629) are inverse but often only one direction is given, making queries more complicated. I found more then 800 missing statements in 9/2017. I added the missing direction for

items subclass/instance of knowledge organization system (Q6423319)
items subclass/instance of unique identifier (Q6545185) and properties subclass/instance of Wikidata property for authority control (Q18614948)

some statistics edit

This table lists some identifier properties and statics on the uniqueness **of their use** in Wikidata.

See also function (Q11348) (values per item unique) and injection (Q182003) (both unique).

Property	Total uses	values per item	items per value
inventory number (P217)	133344	multiple	multiple
ISO 639-1 code (P218)	184	unique	multiple
ISO 639-2 code (P219)	501	multiple	multiple
ISO 639-3 code (P220)	6879	multiple	multiple
ISO 639-6 code (P221)	8	unique	unique
EC number (P232)	3631	multiple	multiple
FAA airport code (P240)	2283	unique	multiple
ticker symbol (P249)	68	multiple	unique
German district key (P440)	304	unique	unique
Unicode character (P487)	2366	multiple	multiple