Error: "Cannot send headers", when fetching table data (direct SQL query)

Question

I want to get a variable from a table of another module.

I followed this tutorial: https://fishpig.co.uk/magento/tutorials/direct-sql-queries/

$resource = Mage::getSingleton('core/resource');
$readConnection = $resource->getConnection('core_read');
$query = 'SELECT * FROM ' . $resource->getTableName('catalog/product');
$results = $readConnection->fetchAll($query);
var_dump($results);

and it works great for catalog/product table.

Then I tried to do the same thing for the custom table from a module:
$query = 'SELECT * FROM ' . $resource->getTableName('amtable/rate');

I concluded that the "table name" should be amtable/rate by following this comment and looking at the config.xml:

<global> <models> <amtable> <class>Amasty_Table_Model</class> <resourceModel>amtable_mysql4</resourceModel> </amtable> <amtable_mysql4> <class>Amasty_Table_Model_Mysql4</class> <entities> <method> <table>am_table_method</table> </method> <method_store> <table>am_table_method_store</table> </method_store> <rate> <table>am_table_rate</table> </rate> </entities> </amtable_mysql4>
But I get an error:
Cannot send headers; headers already sent in app/code/local/Jurgis/Mymodule/controllers/IndexController.php, line 15

Line 15 is: var_dump($results);

What could I be doing wrong or is there something I'm missing?

P.S. sorry about the formatting, couldn't figure out how to fix it.

• Amit Bera: yes, var_dump($results); is create s issue.It is try to reset header.Best way to use log
• Metal Mathematician: How do I print out an array like that using a log?
• Brett: print_r($var, true) will return the array as a string representation.

Answer 1

Still not sure what was causing it, but it was fixed by adding exit(); after var_dump($results);

Hope this helps someone.