PHP : Convert CSV to JSON with YQL example

Just a note for myself for future reference. Putting this down here...maybe you may find it useful too.

This tutorial will cover how to download CSV data from Yahoo Finance and then convert the CSV data to JSON response in PHP.

1. The URL for downloading CSV data is

   http://download.finance.yahoo.com/d/quotes.csv?s=%5EIXIC&f=sl1d1t1c1ohgv&e=.csv

   You can get the URL from http://finance.yahoo.com/q?s=%5EIXIC and see the bottom-right corner - under tool box.

2. Next, visit Yahoo Developer and setup the query at https://developer.yahoo.com/yql

3. Once you configured your query, you can copy the select statement from YQL and use it in your PHP source code. Use file_get_contents() and json_decode() functions to convert the CSV data into JSON response.

For example :

 $BASE_URL = "http://query.yahooapis.com/v1/public/yql";

 $YQL_QUERY = "select * from csv where url='http://download.finance.yahoo.com/d/quotes.csv?s=%5EIXIC&f=sl1d1t1c1ohgv&e=.csv' and columns='symbol,price,date,time,change,col1,high,low,col2'";

 $YQL = $BASE_URL . "?q=" . urlencode($YQL_QUERY) . "&format=json";

 $data = file_get_contents($YQL);

 $decoded = json_decode($data);
 //echo "<pre>";
 //print_r($decoded);
 //echo "</pre>";

 $last_price = $decoded->query->results->row->price;
 $change = $decoded->query->results->row->change;
 $high = $decoded->query->results->row->high;
 $low = $decoded->query->results->row->low;

NOTE : Rate Limits

Use of the YQL should not exceed reasonable request volume. Access is limited as below:

Per application limit (identified by your Access Key): 100,000 calls per day

Per IP limits: /v1/public/*: 2,000 calls per hour; /v1/yql/*: 20,000 calls per hour