Magento getProductCollection not working. - magento

Question

Here is my Magento code to get all new products but it has suddenly stopped working. I added some new categories and then when I saw frontend New Arrivals section was empty. Any help would be appreciated.
Here is my code:
<?php if (($_products = $this->getProductCollection()) && $_products->getSize()): ?>
<div class="new-products">
<div class="title_index">
<!-- <div class="pagination_carousel" id="foo3_pag"></div>-->
<h2><?php echo $this->__('New Arrivals') ?></h2>
</div>
<div class="index_cont">
<div class="list_carousel">
<ul id="user_interaction">
<?php $_columnCount = $this->getColumnCount(); ?>
<?php $i=0; foreach ($_products->getItems() as $_product): ?>
<li><h3 class="product-name"><?php echo $this->htmlEscape($_product->getName()) ?></h3>
<img src="<?php echo $this->helper('catalog/image')->init($_product, 'small_image')->resize(220, 200) ?>" width="150" height="130" alt="<?php echo $this->htmlEscape($_product->getName()) ?>" />
<div class="descr"><?php echo($_product->getSku()); ?></div>
<div class="new_price"><?php echo $this->getPriceHtml($_product, true, '-new') ?></div>
<div class="new_pr_btn"><input value="1" type="text" name="qty" class="my-qty-box" /><button type="button" title="<?php echo $this->__('Add to Cart') ?>" class="button btn-cart" onclick="setLocation('<?php echo $this->getAddToCartUrl($_product) ?>')"><span><span><?php
echo $this->__('Add to Cart') ?></span></span></button></div>
</li>
<?php endforeach; ?>
</ul>
<div class="clear"></div>
</div>
</div>
<div class="shadow-div"></div>
</div>
<?php endif; ?>
Thanks
Dani

Answer 1

$sql=$this->getProductCollection()->getSelect(); place this code at top of your phtml.
echo $sql;
This will show you sql qquery.
Now fire this query directly in phpMyAdmin or miniadmin and check whether you have records for this query or not.
If not diagnose this sql query, think of filters that resulted in some conditions this will lead you to a fix.
Else you paste sql query here for further comments.
Note : if flat catalog is on code will check flat catalog table.So check if these tables do have all products opulated.If not run indexing.