title: Magento getCollection() in Grid returns false
body: <p>I'm currently in the process of learning how to work with the Magento backend. I have created a model class <code>example/event</code> and a corresponding resource. I am able to add records (via a Magento admin form) to a DB table I have created <code>example_event</code>. I am having trouble however retrieving records from my table. My Gird class is as follows:</p>
  
  <pre><code>class MasteringMagento_Example_Block_Adminhtml_Event_Grid extends Mage_Adminhtml_Block_Widget_Grid {
  
      protected function _prepareCollection() {
          $collection = Mage::getModel('example/event')-&gt;getCollection();
          var_dump($collection); // bool(false)
  
          //$record = Mage::getModel('example/event')-&gt;load(1); //id from example_event table
          //var_dump($record); // returns object record as expected
  
          $this-&gt;setCollection($collection);
  
          return parent::_prepareCollection();
      }
  
      protected function _prepareColumns() {
          $this-&gt;addColumn('name', array(
                 'type'=&gt;'text',
                 'index'=&gt;'name',
                 'header'=&gt;$this-&gt;__('Name')
          ));
  
          $this-&gt;addColumn('start', array(
                 'type'=&gt;'date',
                 'index'=&gt;'start',
                 'header'=&gt;$this-&gt;__('Start Date')
          ));
  
          $this-&gt;addColumn('end', array(
                 'type'=&gt; 'date',
                 'index'=&gt;'end',
                 'header'=&gt;$this-&gt;__('End Date')
          ));
  
          return $this;
      }
  
  }
  </code></pre>
  
  <p>As noted in the code, <code>$collection = Mage::getModel('example/event')-&gt;getCollection()</code> returns false. However I am able to retrieve a single record from my database table by using <code>$record = Mage::getModel('example/event')-&gt;load(1);</code> where 1 is the ID of the record (this is simply a sanity check to ensure that at least something I wrote can talk to the DB). The goal is to render the collection to the grid built by the <code>_prepareColumns()</code> function.</p>
  
  <p>Again, I am brand new to programming in the Magento backend, but I have been through my code over and over and cannot seem to figure out why my collection object is empty.</p>