Yahoo! Query Language

Yahoo! Query Language - YDN

Yahoo! Query Language

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?

1. Check out the YQL Console.
2. Read how to access YQL from your
   application.
3. Get your API Keys to sign your requests if
   you need them.
4. Check out the YQL frequently asked questions (FAQ) for answers to common issues.

Using the API or Web Service

• YQL Overview

  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.

  Examples:

  • 
    Zillow
  • 
    Yelp
  • 
    Pidgets Geo IP

• YQL Execute

  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.

  Execute elements run server-side JavaScript with
  E4X (native XML) support. This gives developers a
  fully functional language that Web developers know,
  and lets them do almost anything they want with the
  data. We've added a few new global objects to the
  language to enable developers to: include
  JavaScript libraries and code from any URL; fetch
  data from any URL/Web page; run other YQL commands;
  and perform data filtering and conversion.

  Examples:

  • CSS selectors for HTML
    - a CSS selector table for getting data
    from HTML pages

    use
"http://yqlblog.net/samples/data.html.cssselect.xml";


    select * from data.html.cssselect;

    Try CSS
    selectors.

  • 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'

    Try
    Unified web+image search.

• 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 update to Yahoo! Updates,
    not just list them
  • add new comments to a blog,
    as well as read them
  • store data in a remote
    database
  • INSERT INTO Internet

  Open Data Table (ODT) developers can add support
  for these verbs into their tables by creating new
  binding types in their ODT definitions. They can
  then perform the insert/update/delete on the remote
  web service by creating an execute element that
  runs their JavaScript to create the right content
  payload and send it to the remote service. We've
  extended the capabilities in our server-side
  JavaScript, so y.rest() can now POST, PUT and
  DELETE.

  Try creating a new Yahoo! update from the YQL console by
  following this link:
  
  
  INSERT INTO social.updates (guid, title, description) VALUES (me, "Using YQL", "Try YQL, it's fun.");

Using YQL for Commercial and Non-Commercial
Applications

Our goal is to make it easy for you to use YQL in the
widest possible range of applications. Please read the
notice and usage limits described below for more
information. If you have additional questions, please read
the YQL
Terms of Service and/or contact us at the email address
below.

Notice

• YQL can be used for commercial
  purposes
• If we're going to shut down YQL, we
  will give you at least 6 months notice with an
  announcement on this web page and in our forum
• YQL has a performance uptime target
  of over 99.5%

Usage Limits

• Per application limit (identified
  by your Access Key): 100,000 calls per day
• Per IP limits: /v1/public/*: 1,000
  calls per hour; /v1/yql/*: 10,000 calls per hour

Additional Notes

• All rates are subject to
  change
• You may also be subject to the
  underlying rate limits of other Yahoo! and 3rd party
  web services
• YQL relies on the correct operation
  of the web services and content providers it
  accesses

Please send email to yql-questions [at] yahoo-inc.com
with requests for additional information.

Information for content and API providers

If you are a content or API provider and would like to learn how to opt out, or work better with YQL, please check our provider page.

Support and Community

Questions and suggestions on YQL are discussed on the YQL
Developer Community forum. If you have questions or
need technical support, please use this forum.