What is YQL?
The Yahoo! Query Language is an expressive SQL-like language that lets you query, filter, and join data across Web services. With YQL, apps run faster with fewer lines of code and a smaller network footprint.
Yahoo! and other websites across the Internet make much of their structured data available to developers, primarily through Web services. To access and query these services, developers traditionally endure the pain of locating the right URLs and documentation to access and query each Web service.
With YQL, developers can access and shape data across the Internet through one simple language, eliminating the need to learn how to call different APIs.
How Do I Get Started?
- Check out the YQL Console.
- Read how to access YQL from your application.
- Get your API Keys to sign your requests if you need them.
Using the API or Web Service
YQL exposes an SQL-like SELECT syntax that is both familiar to developers and expressive enough for getting the right data. Through the SHOW and DESC commands, we enable developers to discover the available data sources and structure without opening another Web browser.
YQL Open Data Tables
Open Data Tables enable developers to add tables for any data on the Web to our stable of API-specific tables. Using Open Data Tables, anyone can make their data YQL-accessible. If you would like to create an Open Data Table, visit the community page at http://datatables.org.
Building upon Open Data Tables, the Execute element gives developers full control of how the data is fetched into YQL and how it's presented back to the user. With Execute, developers can build tables that manipulate, change, and sign the URLs to access almost any protected content. This lets YQL access and combine data across a variety of different authenticated services such as Netflix or Twitter. Developers can call multiple services and data sources within Execute to join and mash up data however they desire, letting Yahoo! do the work rather than their applications. Data can be tweaked and manipulated into an optimal format for applications to consume.
CSS selectors for HTML - a CSS selector table for getting data from HTML pages
select * from data.html.cssselect;
Unified web+image search - perform a BOSS search that also returns an image from the BOSS image search for the same site and query term in a single result set
use 'http://yqlblog.net/samples/search.imageweb.xml' as searchimageweb;
select * from searchimageweb where query='pizza'
YQL Insert/ Update/ Delete
You can use YQL to write and modify data on Web services and applications using SQL keywords: INSERT, UPDATE, and DELETE. These verbs let you manipulate data mapped onto an Open Data Table and enables developers to use Open Data Tables to do the following:
- insert new Twitter status messages, not just list them
- add new comments to a blog, as well as read them
- store data in a remote database
- INSERT INTO Internet
Try creating a new tweet from the YQL console by following this link:
use 'http://www.yqlblog.net/samples/twitter.status.xml'; insert into twitter.status (status,username,password) values ("Playing with INSERT, UPDATE and DELETE in YQL", "twitterusername","twitterpassword")
YQL has the following API usage restrictions:
Per application limit (identified by your Access Key):
- 100,000 calls per day.
Per IP limits:
- /v1/public/* 1000 calls per hour
- /v1/yql/* 10000 calls per hour
All rates are subject to change. In addition, you may also be subject to the underlying rate limits of other Yahoo and 3rd party web services.
Please contact yql-questions [at] yahoo-inc.com with requests for additional limits and information.