Yahoo Query Language: Select * from Internet

Yahoo Query Language:
select * from internet
Derek Gathright

var map = new YMap(document.getElementById('map'));…varcurrentGeoPoint = new YGeoPoint( _c.Lat, _c.Lon ); map.addMarker(currentGeoPoint);…
…
if (flickcurl_prepare(fc, "flickr.photos.geo.correctLocation", parameters, count)) { … }
…
http://search.yahooapis.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&query=Corvette&results=2
http://weather.yahooapis.com/forecastrss?p=FRXX0076&u=c

var map = new YMap(document.getElementById('map'));…varcurrentGeoPoint = new YGeoPoint( _c.Lat, _c.Lon ); map.addMarker(currentGeoPoint);…
…
if (flickcurl_prepare(fc, "flickr.photos.geo.correctLocation", parameters, count)) { … }
…
http://search.yahooapis.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&query=Corvette&results=2
http://weather.yahooapis.com/forecastrss?p=FRXX0076&u=c
YQL
YQL stmt

Why YQL?
Thousands of Web Services and sources that provide valuable data
Require Developers to read documentation and form URLs/queries.
Data is isolated
Needs filtering, combining, tweaking, shaping even after it gets to the developer.

What is YQL?
Cloud web service and SQL-Like Language
Familiar to developers
Synonymous with Data access
Expressive enough to get the right data.
Self describing - show, desc table
Allows you to query, filter, join and update data across any structured data on the web / web services
And Yahoo’s sherpa cloud storage
Real time engine

YQL Statement Basics
show: lists the supported tables
desc: describes the structure of a table
select: fetches data
insert/update/delete: modify data
use: use an Open Data Table
set: define key-values across Open Data Tables

Insert / Update / Delete
With INSERT/ UPDATE/ DELETESQL verbs you can modify data on the internet or cloud
create tweets, add blog entries, update DBs etc
store tables or pieces of code in sherpa
Some tables with I/U/D
Twitter, Bit.ly shortener
Yahoo profile status, application update stream
Amazon SimpleDB

Demo: developer.yahoo.com/yql/

Get any data:
Open Data Tables

Open Data Tables
http://github.com/yql/yql-tables/tree/master
datatables.orgmirrors the master and builds a single environment with all tables (faster serving)
Console with community tables
Brings the power of the table model to new APIs
Schema defines mapping between YQL and Endpoint
Keys can either be query, path or matrix parameters
Keys can be marked as required
YQL Compiler validates existence of required keys

YQL
Open Data Table example

Open Data Table example

ODT <execute> element
Extends Open Data Tables with server-side code
Javascript server-side scripting
No DOM, events etc, pure JS scripting
E4X support - XML literals, filtering ...
YQL no longer performs a GET request to the table binding URL
YQL provides additional useful global objects
request, response, y.rest, y.include, y.query...
Execute tag must return the data that will be the output of the YQL select
Move business logic of your application to the cloud

What you can do with <execute>
access APIs that require authentication
Netflix OAuth, FlickrAuth, Google AuthSub
join data across services
grab New York Times article tags and generate find associated flickr photos
combine multiple searches into a single result (twitter, web, news and images)
augment data:
city/state to APIs that just return zip code
create APIs from web page
celebrity birthdays scraped from imdb, caltrain
data transformation
convert the result from xml to Google's kml format

hello world
<table xmlns="http://query.yahooapis.com/v1/schema/table.xsd">
<meta>
<sampleQuery>select * from {table} where a=’hello' and b=’world';</sampleQuery>
</meta>
<bindings>
<select itemPath="" produces="XML">
<urls><url>http://fake.url/{a}</url></urls>
<inputs>
<key id='a' type='xs:string' paramType='path' required="true" />
<key id='b' type='xs:string' paramType='variable' required="true" />
</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>
</table>

Scraping a page
<select produces="XML" itemPath="deals.deal">
<urls><url>http://deals.yahoo.com</url></urls>
<execute><![CDATA[
vardealhtml = y.query("select * from html where url='http://deals.yahoo.com' and xpath='//div[contains(@class, "product-display")]'").results;
var deals = <deals/>;
function compress(object) {
if (!object) return "";
return object.toString().replace(/s+/, " ")
}
for each (var div in dealhtml.div) {
var deal = <deal/>;
deal.name += <name>{compress(div.h3.a.text())}</name>;
deal.link += <link>{div.div[0].a.@href}</link>;
…
deal.description += <description>{compress(div.p[0].*)}</description>;
deal.logo += <logo>{compress(div.div[1].*)}</logo>;
deals.deal += deal;
}
response.object = deals;
]]></execute>
</select>

Twitter Select
select *from twitter.statuswhere id="2108869549"andusername="xxx"and password="yyy”
<select itemPath="" produces="XML">
<urls><url>http://twitter.com/statuses/show/{id}.xml</url></urls>
<inputs>
<key id="username" type="xs:string" required="false" paramType="variable"/>
<key id="password" type="xs:string" required="false" paramType="variable"/>
<key id="id" type="xs:integer" required="true" paramType="path"/>
</inputs>
<execute><![CDATA[
varr = null;
if (username && password) {
y.include("http://yqlblog.net/samples/base64.js");
varauthheader = "Basic "+Base64.encode(username+":"+password);
r = request.header("Authorization",authheader).get().response;
} else {
r = request.get().response;
}
response.object = r;
]]></execute>
</select>

Twitter Update
insert into twitter.status(status,username,password)values ("new tweet from YQL",”xxx”,”yyy”);
<insert itemPath="" produces="XML">
<urls>
<url>http://twitter.com/statuses/update.xml</url>
</urls>
<inputs>
<value id="username" type="xs:string" required="true" paramType="variable"/>
<value id="password" type="xs:string" required="true" paramType="variable"/>
<value id="status" type="xs:string" required="true" paramType="variable"/>
</inputs>
<execute><![CDATA[
var content = "status="+status;
response.object = request.header("Authorization",authheader).post(content).response;
]]></execute>
</insert>

Twitter Delete
delete from twitter.statuswhere id="2108869549"and username="xxx"and password="yyy”
<delete itemPath="" produces="XML">
<urls>
<url>http://twitter.com/statuses/destroy/{id}.xml</url>
</urls>
<inputs>
<key id="username" type="xs:string" required="true" paramType="variable"/>
<key id="password" type="xs:string" required="true" paramType="variable"/>
<key id="id" type="xs:string" required="true" paramType="path"/>
</inputs>
<execute><![CDATA[
response.object = request.header("Authorization",authheader).del().response;
]]></execute>
</delete>

Conclusion
More easily build applications
fewer lines of code
data processing done away from app
consistent and familiar syntax for all data access

Conclusion
Build applications that run faster
service in the cloud does the work
store tables, environments, js, text files…
conversion, filtering, parallel requests...
With smaller network footprint
fewer (client) calls
smaller data amounts
closer to the data, fatter pipes

Conclusion
Flexible
Supports XML, JSON, JSONP
Transform documents between formats
Easy to integrate into any development environment w/ HTTP

Questions?
http://developer.yahoo.com/yql
Derek Gathright
drg@yahoo-inc.com
twitter.com/derek
meetup.com/socaljs

Yahoo Query Language: Select * from Internet

by drgath on Apr 21, 2010

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