User:Geertivp/training/Wikidata Query

Wikidata Queries

Wikidata Query is a tool to query Wikidata. It uses SPARQL to process your query on RDF data.

The result of a query can be used again to update Wikidata, to automatically add missing data, or correct (constraint) errors/inconsistencies/constraint violations.

This way you can start a cycle of continuous improvement. You will typically use QuickStatements to process your transactions.

Here I will show a simple example how to create missing labels in a target language. Other queries are available from Wikidata Queries.

Why we need Wikidata Query to verify Data quality/completeness?[edit]

Constraints[edit]

Wikidata is extremely open
Anyone can edit
Constraints are not proactively checked => only visible after saving the data

Culture[edit]

The importance of languages:

Multilingual countries
EN is most used
Get your language/culture known in EN => others will translate/build in their own language
Add a WM link

Search for missing labels in a target language[edit]

Search for Labels from other languages that do not exist in the target language. The results can be input for QuickStatements 2 (Q29032512) (see QuickStatements). This way you can semi-automatically create Labels (and the Description for the item) in any target language.

Example query[edit]

Copy the following code to https://query.wikidata.org and click on Execute query:

The following query uses these:

Items: human (Q5)   , Belgium (Q31)

Properties: instance of (P31)  

, country of citizenship (P27)  

# Duplicate Labels to other languages
SELECT ?item ?itemLabel ?itemDescription WHERE {
 ?item wdt:P31 wd:Q5.  #instance of human
 ?item wdt:P27 wd:Q31. #country of citizenship Belgium
 
 SERVICE wikibase:label { bd:serviceParam wikibase:language "en,nl,fr,de,it,lu,es,no,pt". }
 FILTER(NOT EXISTS {
   ?item rdfs:label ?lang_label.
  FILTER(LANG(?lang_label) = "en") #with missing English label
 })
 }
 ORDER BY ?itemLabel

Try it!

Results[edit]

Column	Description
item	Q-number
itemLabel	Label in source language
itemDescription	Description in source language

Process[edit]

Export to Excel (problem with download: bad accents with UTF-8 character set; use copy/paste instead)
Remove rows with missing labels
Remove rows with missing descriptions
Translate descriptions (use Wikidata)
Prepare a QuickStatements load file
Execute the transactions (copy/paste to QuickStatements ⇒ try one row first)
Verify the results
Manually correct any errors

Load file example[edit]

There exists a V1 or V2 transaction format.

Execute transactions via https://tools.wmflabs.org/quickstatements/ (short user guide included). First create the Labels:

Q16526046	Len	"Aaron Botterman"
...

and then afterwards the Description:

Q16526046	Den	"Belgian athlete"
...

Authentication[edit]

You need WiDaR to authorize your QuickStatements session
Transactions are logged under your userID

Known problems[edit]

Import accents with proper UTF-8 character set
Use the Lxx and Dxx separately (otherwise only the first operation is executed...)
V2 allows for multiple properties to be added, one after the other in columnar format
V2 requires """string""" triple-string-quoting
Network problem could stop the processing; when the network connection is established again only process the rest of the file
Use off-line transaction with large transaction files, when possible
Wikidata Query runs on a replica of the live database, so can be a couple of minutes behind the live update of Wikidata edits/QuickStatements (to verify your results with Wikidata Query you might wait up-to 5 minutes). Verify with "View history" to be sure.

Tips[edit]

You can set your GUI language (same as Wikidata) -- this makes it more easy to work with Properties
Preferably use English as target language; it has the most items/users ⇒ the chance that your item is amended in yet another languages is higher...
You can easily take one query (as an example) and change a few properties/values to create simular queries
You can use checkConstraints to see constraint problems

External links[edit]

Tools

Documentation

Other

Obsolete

Wikidata to QuickStatements tool