Question

I am working on a magento admin module and currently I am running a database query in a sloppy fashion, by directly loading a php file and connecting with a php file outside of the module:

<?php 
header("Content-type: text/xml");
$host           = "localhost";
$user           = "root";
$pw             = "foo";
$database       = "db";
$link           = mysql_connect($host,$user,$pw) or die ("Could not connect.");
$db_selected = mysql_select_db($database, $link); if (!$db_selected) {
    die ('Can\'t use ' . $database . ' : ' . mysql_error()); }


// connect to database
$link   = mysql_connect($host . ":" . $port,$user,$pw) or die ("Could not connect.");

// Select DB
$db_selected = mysql_select_db($database, $link); if (!$db_selected) {
    die ('Can\'t use ' . $database . ' : ' . mysql_error()); }

// Database query
$query = ("SELECT cpsl.parent_id AS 'foo'
  , cpe.type_id AS 'bar'
  , LEFT(cpe.sku, 10) AS 'color'
  ....
GROUP BY 1,2,3,4,5,6,7,8,9
ORDER BY 1,2,3,4,5,6,7,8,9
;");

// Execute query
$result = mysql_query($query, $link) or die("Could not complete database query");

// Populate array
while(($resultArray[] = mysql_fetch_assoc($result)) || array_pop($resultArray));

  $doc = new DOMDocument();
  $doc->formatOutput = true;

  $r = $doc->createElement( "DATA" );
  $doc->appendChild( $r );

  foreach( $resultArray as $product )
  {
  $b = $doc->createElement( "ITEM" );

  // MagentoID
  $magento_id = $doc->createElement( "MAGENTO_ID" );
  $magento_id->appendChild(
  $doc->createTextNode( $product['MagentoID'] )
  );
  $b->appendChild( $magento_id );
....

 }

// Save XML
  echo $doc->saveXML();

// Close connection
mysql_close($link);

?>

Can someone please explain a better way to write this into the module? I know I can make the connection much easier (more secure?) using magentos methods. Can I put this whole query directly in the controller for the module? Something like this? :

public function queryAction()
    {
$readConnection = $resource->getConnection('core_read');
$query = ("SELECT cpsl.parent_id AS 'foo'
...
}

Answer 1

Yes, you can do what you propose.

I have something like the following:

class Foo {
    protected $db;

    public function _construct() {
        /* Change core_write to core_read if you're just reading */
        $this->db = Mage::getSingleton('core/resource')->getConnection('core_write');
    }

    private function doAQuery() {
        $sql = "SELECT * FROM foobar f;";
        $data = $this->db->fetchAll($sql);
        /* do something with the data here */
    }

    private function doAQueryADifferentWay() {
        $sql = $this->db->select();
        $sql->from(array('f' => 'foobar'));
        $data = $this->db->fetchAll($sql);
        /* do something with the data */
    }
}

edited to add

You can make the call directly from the controller by defining the methods in the controller and calling them with something like $this->doAQuery(); I’m a pretty big fan of putting things in the right place for easier maintainability, though, so I’ll outline the steps needed to do that.

I’m going to assume you know how to/can read the docs on how to create a skeleton module, but I may end up talking down a bit. Apologies in advance.

For the sake of argument, I’m going to call our example module Zac_Example. So we’ll pretend we have a module in app/code/local/Zac/Example. Any further paths will assume we’re starting in that directory.

First, you need to define a model (I guess you could use a helper if you prefer) and controller, so we define those in etc/config.xml

...
  <frontend>
    <routers>
      <zac_example>
        <use>standard</use>
        <args>
          <module>Zac_Example</module>
          <!-- Mind the capital N, it gets me every time -->
          <frontName>example</frontName>
        </args>
      </zac_example>
    </routers>
  </frontend>
  <global>
    <models>
      <zac_example>
        <class>Zac_Example_Model</class>
      </zac_example>
    </models>
  </global>
...

Now we define our model in Model/Query.php, which is Foo from above, but using the Magento naming convention:

class Zac_Example_Model_Query extends Mage_Core_Model_Abstract {
    protected $db;

    /* you don't have to do this, as you can get the singleton later if you prefer */
    public function __construct() {
        $this->db = Mage::getSingleton('core/resource')->getConnection('core_write');
    }

    public function doAQuery() {
        /* If you chose not to do this with the constructor:
         * $db = Mage::getSingleton('core/resource')->getConnection('core_write');
         */

        $sql = "SELECT * FROM foobar f;";
        /* or $db->fetchAll($sql); */
        $this->db-fetchAll($sql);
        /* do something with the data here */
        return $response
    }

    public function doAQueryADifferentWay($somerequestdata) {
        $sql = $this->db->select();
        $sql->from(array('f' => 'foobar'));
        $sql->where('f.somedata', array('eq' => $somerequestdata));

        $data = $this->db->fetchAll($sql);
        /* do something with the data */
    }
}

Now, having a model, we can set up a controller. We’ll call the controller test, so the following goes in controllers/TestController.php. The actions, we’ll call foo and bar.

class Zac_Example_TestController extends Mage_Core_Controller_Front_Action {

    public function fooAction() {
        $model = Mage::getModel('zac_example/query');
        $result = $model->doAQuery();
        $this->getResponse()->setBody(Zend_Json::encode($result));
        $this->getResponse()->sendResponse();
        exit; // We're done, right?
    }

    /* This assumes the request has a post variable called 'whatever' */
    public function barAction() {
        $model = Mage::getModel('zac_example/query');
        $param = $this->getRequest()->getParam('whatever');
        $result = $model->doAQueryADifferentWay($param);
        $this->getResponse()->setBody(Zend_Json::encode($result));
        $this->getResponse()->sendResponse();
        exit; // We're done, right?
    }

Given that particular set of facts, the URLs in question would be http://yourserver/example/test/foo and http://yourserver/example/test/bar. If we had named the controller file IndexController.php, they would be http://yourserver/example/index/foo and http://yourserver/example/index/bar.

If you only have one action you need to make available, you can name the controller file IndexController.php and the method in the controller indexAction and use the URL http://yourserver/example/.

I’m shooting from the hip, so don’t be surprised if there’s at least one braino or typo somewhere.