Editing Encyclopedia:Database queries

{{nutshell
|shortcut1=WP:DQ
|shortcut2=WP:SQL
|Queries can be run against the Wikipedia database in a variety of ways.}} 

== Overview ==

Much of the data that makes up the Wikipedia encyclopedia is stored in a [[SQL database]].  It can sometimes be useful to run queries against this database to extract information that is otherwise hard to find.  For example:

* Articles with ''H.M.S.'' in their title that have not been edited for 12 months.
* [[WP:Redirect|Redirects]] with fewer than 20 incoming links that redirect to [[WP:Category|categories]]
* All [[WP:Red link|red links]] on pages within the scope of a particular [[WP:WikiProject|WikiProject]] 

Many simple queries can be run directly using the tools built into the [[MediaWiki]] package used by Wikipedia. Some of the most popular and useful queries are run regularly and can be found at [[Wikipedia:Database reports]]. If neither of these suits your query, you can [[Wikipedia:Request a query|request]] that someone run a query for you, or download your own copy of the database to work on.

== Using the MediaWiki tools ==
Some queries can be satisfied through the MediaWiki interface:

* [http://en.wikipedia.org/w/index.php?title=Special:Search&search=&fulltext=Search&profile=advanced&redirs=1 Search in advanced mode]
* [[Special:PrefixIndex|All pages with prefix]]
* [[Special:CategoryTree|Category tree]]
* [[mw:API|MediaWiki API]] (see [[Special:ApiSandbox]])

== Queries that are already run regularly ==
Useful queries that are regularly run can be found at:

* [[Special:SpecialPages]]
* [[Wikipedia:Database reports]]
* [[Wikipedia:Statistics]]

And many other places.

== Run a query ==
All Wikipedians have the ability to run queries on a copy of the live database on the [[WP:Wikimedia Cloud Services|Wikimedia Cloud VPS]] called [//quarry.wmflabs.org/ Quarry].

== Request a query ==
* [[Wikipedia:Request a query]]

== See also ==
*[[wikitech:Nova Resource:Tools/Tools/Query service]]