A Guide To WDQS: A long-form introduction to WDQS. You can start with no knowledge about Wikidata or SPARQL at all and hopefully emerge knowing how to use WDQS for awesome queries. Note that it is perhaps somewhat verbose, and certainly not intended to be useful as a quick reference.
Problems: I maintain a list of some SPARQL queries I wrote that can help you to find problems in Wikidata. Some of the problems could be fixed fully automatically, others need manual review.
wdqs.sty: A LaTeX package that emulates the Wikidata Query Service’s syntax highlighting (font + colors). Could be useful for presentations.
Latest Population: Many German cities had lots of timestamped population (P1082) statements with normal rank; I set the latest one to preferred rank (under certain conditions).
Embedding WDQS: This importable notebook allows you to embed WDQS result views in your notebook.
Replace qualifiers: This importable notebook lets you replace the property of qualifiers of certain statements (by adding a new qualifier with the correct property ID and then removing the old qualifier).