Shreeniwas Iyer of the Yahoo! Singapore office provides an overview of the Yahoo! Query Language

1. Standardizing web querying - Using YQL
for accessing and exposing APIs

2. Agenda
• Introduction to YQL
• How to get started
• What’s supported through YQL
• Theme of the day – mim.yahoo.com
• Lots of examples using mim API
• Mashup using YQL
• Introduction to more YQL goodies
-Server side javascript execution
-YQL hosted storage
• Concluding remarks
..lets keep it interactive

3. YQL – Yahoo Query Language
• Enables you to access Internet data with SQL-like commands
• YQL hides the complexity of Web service APIs by presenting data as
simple tables, rows, and columns.
• YQL includes pre-defined tables for popular Yahoo! Web services such
as Flickr, Search, Geo and Mim.
• YQL can access services on the Internet that output data in the
following formats: HTML, XML, JSON, RSS, Atom, and microformat.
• Create fast mashups reducing latency, code

4. How to get started
• Explore the APIs - http://developer.yahoo.com/everything.html
• Get a developer key - https://developer.apps.yahoo.com/wsregapp/
• Read the documentation - http://developer.yahoo.com/yql/guide/
• Visit the YQL Console - http://developer.yahoo.com/yql/console/
-The YQL Console enables you to run YQL statements interactively from your
browser.
• Hack away..

5. Y! APIs supported by YQL
-Show tables
-Flickr
-Y! geo
-Y! local search
-Y! maps
-Y! mim
-Y! music
-Y! MyBlogLog
-Y! search
-Y! social
-Y! upcoming

6. External APIs supported by YQL
- Amazon ECS
- AWS
- Bit.ly
- Comicvine
- Craigslist
- Del.icio.us
- Dopplr
- Facebook
- Friendfeed
- Github
- Google (News, Search,
Translate)
- Guardian
- IMDB
- LastFm
- MediaWikiAPI
- Microsoft (Bing)
- Twitter
- Zillow
Through datatables.org
Show tables

7. Theme of the day – mim.yahoo.com
• Mim has an YQL based API for everything – reading, searching,
updating, deleting and so on.
-Profile information of mim users
-Followers/following information
-Query for users
-Listing mim posts of a user
-Popular posts
-Search for posts
-Inserting (posting to mim) through YQL
 Reposting, commenting deleting

8. Getting information about self (logged in)
<query xmlns:yahoo="http://www.yahooapis.com/v1/base.rng" yahoo:count="1”
yahoo:lang="en-US”
yahoo:uri="http://query.yahooapis.com/v1/yql?q=select+*+from+meme.info+where+owner_
guid%3Dme">
<results>
<meme>
<guid>NKADUBBZPUQQG6GF6AHTDTABSQ</guid>
<name>shreeni</name>
<title>Shreeni&amp;#39;s Mim</title>
<description/>
<url>http://meme.yahoo.com/shreeni/</url>
<avatar_url>http://a.com/b.jpeg</avatar_url>
<language>en</language>
<followers>18</followers>
</meme>
</results>
</query>
select * from meme.info where owner_guid=me

9. In JSON
{"query": {
"count": "1", "created": "2009-11-19T10:33:11Z",
"lang": "en-US", "updated": "2009-11-19T10:33:11Z",
"uri":
"http://query.yahooapis.com/v1/yql?q=select+*+from+meme.info+where+owner_guid%3Dm
e",
"results": {
"meme": {
"guid": "NKADUBBZPUQQG6GF6AHTDTABSQ",
"name": "shreeni", "title": "Shreeni&#39;s Mim",
"description": null,
"url": "http://mim.yahoo.com/shreeni/",
"avatar_url":
"http://d.yimg.com/gg/shreeni/avatars/7a0d55f7d0aab9e326a7906a110f8027d46bd49b.jpeg
",
"language": "en", "followers": "18"
}}}}
select * from meme.info where owner_guid=me

10. How to run YQL queries
•Convert to URL:
http://query.yahooapis.com/v1/public/yql?q=<yql_query>&format=<json/xml>
•Use the YQL Console - http://developer.yahoo.com/yql/console/
•Use a PHP SDK provided by Y! - http://developer.yahoo.com/social/sdk/#php

11. Selecting specific fields
<results>
<meme>
<title>Shreeni&amp;#39;s Mim</title>
<url>http://mim.yahoo.com/shreeni/</url>
<avatar_url>http://d.yimg.com/gg/shreeni/avatars/7a0d55f7d0aab9e326a7906a11
0f8027d46bd49b.jpeg</avatar_url>
<language>en</language>
</meme>
</results>
select title, url, avatar_url, language from meme.info
where name='shreeni'

12. Selecting specific fields (also Followers API)
<results>
<meme>
<name>herry</name>
</meme>
<meme>
<name>grahamhills</name>
</meme>
<meme>
<name>fizzycitrus</name>
</meme>
</results>
select name from meme.followers where owner_guid =
“NKADUBBZPUQQG6GF6AHTDTABSQ”

13. Sub-select and Limits
<results>
<meme>
<name>herry</name>
</meme>
<meme>
<name>grahamhills</name>
</meme>
</results>
select name from meme.followers where owner_guid in
(select guid from meme.info where name='shreeni’)
limit 2

14. Functions
select name from meme.followers where owner_guid in
(select guid from meme.info where name='shreeni') |
sort(field="name", descending="true”)

15. Functions
- Sort
- Tail
- Truncate
- Reverse
- unique
- Sanitize

16. Following API in mim
select name from meme.following where owner_guid in
(select guid from meme.info where
name='bangwinissimo')

17. Searching for people
select guid, name, title, language from meme.people
where query="Fajar”
select guid, name, title, language from meme.people
where query="Fajar" and language=”id"

18. Finding specific Posts of a mim user
select * from meme.posts where owner_guid in (select
guid from meme.info where name='bangwinissimo')
select * from meme.posts where owner_guid in (select
guid from meme.info where name='bangwinissimo') and
type='text'

19. Popular Posts
select * from meme.popular
select * from meme.popular where locale="id"

20. Search in mim
SELECT * FROM meme.search WHERE query="jakarta”

21. Inserting/Deleting mim posts
INSERT INTO meme.user.posts (type, content) VALUES
("text", "This is a text post from YQL!”)
DELETE FROM meme.user.posts where pubid = "Nswwwmv"

22. Reposting, Commenting
INSERT INTO meme.user.posts (guid, pubid, comment)
VALUES ("S5R44PGJRBLKNEE5GYSRQPTXLQ", "rGCOBCK", "this
is the repost comment”)
INSERT INTO meme.user.comments (guid, pubid, comment)
VALUES ("S5R44PGJRBLKNEE5GYSRQPTXLQ", "rGCOBCK", "meme
rocks")

23. YQL Cheat Sheet
http://bit.ly/yql-cheat-sheet

24. Exposing own API through YQL
<?xml version="1.0" encoding="UTF-8"?>
<table xmlns="http://query.yahooapis.com/v1/schema/table.xsd">
<meta>
<sampleQuery>select * from {table} where query=’q'</sampleQuery>
</meta>
<bindings>
<select itemPath="results" produces="JSON" >
<urls>
<url env="all">http://query-url</url>
</urls>
<inputs>
<key id=”q" type="xs:string" paramType="query" required="true" />
</inputs>
</select>
</bindings>
</table>

25. Now access it through YQL
USE "http://definition-file.xml" AS mytable;
SELECT * FROM mytable WHERE query="whatever”

26. Mashup - introduction
•Finding the Sunrise/Sunset time for Jakarta
•Earthtools api for sunrise-sunset information
•XML based api
•Needs latitude-longitude of the location
•Yahoo Geo API to convert location to latitute-longitude
•Would need 2 different API calls and effort from your side
•Assuming Yahoo API was in JSON would have to deal with 2 formats

27. Solution – Exposing 3rd party API in YQL
<?xml version="1.0" encoding="UTF-8"?>
<table xmlns="http://query.yahooapis.com/v1/schema/table.xsd">
<meta>
<author>Earthtools.org</author>
<documentationURL>http://www.earthtools.org/</documentationURL>
<sampleQuery>select * from {table} where lat='lat' and lon='lon' and day='day' and
month='month' </sampleQuery>
</meta>
<bindings>
<select itemPath="sun" produces="XML" >
<urls>
<url env="all">http://www.earthtools.org/sun/{lat}/{lon}/{day}/{month}/99/1</url>
</urls>
<inputs>
<key id="lat" type="xs:string" paramType="path" required="true" /><!– 3 others -->
</inputs> </select></bindings> </table>

28. Querying for the data
# Get the Lat Long information for Jakarta
select * from geo.places where text="Jakarta" limit 1;
# Now get the sunrise/sunset from earthtools using a
# YQL query
USE
"http://rahukalamcalculator.appspot.com/yql/earthtools
-definition.xml" AS earthtools;
SELECT morning, evening FROM earthtools WHERE
lat="1.365580" and lon="103.827713" and day="21" and
month="11”

29. Combine the queries
# One awesome call!
select * from mytable where (lat,lon) in (select
centroid.latitude, centroid.longitude from geo.places
where text="jakarta") and day="21" and month="11”

30. Mashup – solution highlights
•Exposed a third party API through YQL
•Expressed business logic in Query – readable, maintainable
•Used server side for the actual join
•Less latency
•Use the format you like

31. More goodies – YQL server side execution
•Executing JavaScript allows you to use conditional logic and to format data in a
granular manner.
•Better data shaping and parsing
•Better support for calling external Web service
•Better support for adding, modifying, and deleting data using external Web
services
•Lots of examples and detailed documentation at
http://developer.yahoo.com/yql/guide/yql-execute-examples.html

32. Server Side execution - example
<bindings>
<select itemPath="" produces="XML">
<urls>
…
</inputs>
<execute><![CDATA[
// Your javascript goes here. We will run it on our
servers
response.object = <item>
<url>{request.url}</url>
<a>{a}</a>
<b>{b}</b>
</item>;
]]></execute>
</select>
</bindings>

33. More goodies – YQL Hosted Storage
•Size Limit: You can have up to 1000 records, with each record being up to
100KB.
•Retention Limit: Records not read, updated, or executed at least once every
thirty days may be removed.
•Record Format: Records must be in a text-based format. Examples include
JavaScript code, XML files, Open Data Tables, or YQL environment files.
•Authentication for New Records: All connections to yql.storage.admin must be
authorized using two-legged OAuth. Alternatively, you can create new records
using the YQL console. However, connections to yql.storage do not require
authentication.

34. Storing into YQL
# Just the value
insert into yql.storage.admin (value) values ("example text content")
# Contents of a URL
insert into yql.storage.admin (name,url) values
("newrecord","http://hostingdomain.com/mytable.xml")
# response looks like
<results>
<inserted>
<execute>store://35ad2c72-e353-41c4-9d21-4a7e5a1ec92</execute>
<select>store://08fd2c74-d393-48c4-9ee1-3bf7e5a1ec92</select>
<update>store://3cc85a99-6a89-4600-ade1-f7f83ecc4b83</update>
</inserted>
</results>

35. Querying from hosted storage
# Uses select-id
select * from yql.storage where name="store://08fd2c74”
# Uses update-id
delete from yql.storage where name="store://3cc85a99”
update yql.storage set value="new value" where
name="store://3cc85a99”
# Use contents as env file (uses execute-id)
use "store://35ad2c72" as mytable;
select * from mytable;
# Use contents as JS for server side execute (uses execute-id)
y.include('store://35ad2c72');
response.object = <success>{success}</success>;

36. Concluding remarks
•YQL is an extensible gateway to use APIs across and beyond Yahoo!
•Allows standardization of APIs across the web
•Familiar and concise language for expressing business and data logic
•Powerful tool to build mashups
•You can build upon existing APIs and expose third party APIs
•Sound server side support, including javascript execution and storage to enable
easy development

37. Questions?

38. Thank You!
•http://developer.yahoo.com/yql
•shreeni@yahoo-inc.com
•http://tech.shreeni.info