The YQL Web Service enables applications to query, filter, and combine data from different sources across the Internet. YQL statements have a SQL-like syntax, familiar to any developer with database experience. The following YQL statement, for example, retrieves a list of cat photos from Flickr:
SELECT * FROM flickr.photos.search WHERE text="cat"
To access the YQL Web Service, a Web application can call HTTP GET, passing the YQL statement as a URL parameter, for example:
http://query.yahooapis.com/v1/public/yql?q=SELECT * FROM flickr.photos.search WHERE text="Cat"
When it processes a query, the YQL Web Service accesses a datasource on the Internet, transforms the data, and returns the results in either XML or JSON format. YQL can access several types of datasources, including Yahoo! Web Services, other Web services, and Web content in formats such as HTML, XML, RSS, and Atom.