Add comment box to each product in Magento Cart

Adding a custom comment box for each item in the cart is actually very easy.
First lets add the textarea field for each item.

open file: template/checkout/cart.phtml
Add the new heading along with other heading for cart items.

<th><?php echo $this->__('Comments') ?></th>

Open file: template/checkout/cart/item/default.phtml
Add a new column

<td class="a-center">
<textarea name="cart[<?php echo $_item->getId() ?>][comments]" rows="3" cols="20"><?php echo $_item->getItemcomment() ?></textarea>
</td>

new we need to add this comment in DB so for that we need to add ‘itemcomment’ field in table ‘sales_flat_quote_item’

now open file : app/code/core/Mage/Checkout/Model/Cart.php

now we need to make changes in function updateItems()

 public function updateItems($data)
 {
     Mage::dispatchEvent('checkout_cart_update_items_before', array('cart'=>$this, 'info'=>$data));

     foreach ($data as $itemId => $itemInfo) {

         $item = $this->getQuote()->getItemById($itemId);
         if (!$item) {
             continue;
         }

         if (!empty($itemInfo['remove']) || (isset($itemInfo['qty']) && $itemInfo['qty']=='0')) {
             $this->removeItem($itemId);
             continue;
         }

         $qty = isset($itemInfo['qty']) ? (float) $itemInfo['qty'] : false;
         if ($qty > 0) {
             $item->setQty($qty);
         }

     /* Start: Custom code added for comments */
     if(!empty($itemInfo['comments'])) {

     	$write = Mage::getSingleton('core/resource')->getConnection('core_write');

     	# make the frame_queue active
   		$query = "UPDATE `sales_flat_quote_item` SET itemcomment = '".$itemInfo['comments']."' where item_id = $itemId";
$write->query($query);

     	$item->setItemcomment($itemInfo['comments']);
     }
     /* End: Custom code added for comments */

     }

     Mage::dispatchEvent('checkout_cart_update_items_after', array('cart'=>$this, 'info'=>$data));
     return $this;
 }
 

we need to create new function given below in file app/code/core/Mage/Adminhtml/Block/Sales/Order/View/Items.php

 	public function getItemcomment($item) {
		$itemId = $item->getId();

		$write = Mage::getSingleton('core/resource')->getConnection('core_write');

    	$query = "SELECT q.* FROM `sales_flat_order_item` o
	    LEFT JOIN `sales_flat_quote_item` q on o.quote_item_id = q.item_id
	    WHERE o.item_id = $itemId";

		# For older versions of Magento
/*	    $query = "SELECT q.* FROM `sales_order_entity_int` o
	    LEFT JOIN `sales_flat_quote_item` q on o.value = q.entity_id
	    WHERE o.entity_id = $itemId AND o.attribute_id = 343";       */	    

		$res = $write->query($query);

		while ($row = $res->fetch() ) {
			if(key_exists('itemcomment',$row)) {
				echo nl2br($row['itemcomment']);
			}
		}
	}

To add the comments column to the items edit the .phtml file below:
app/design/adminhtml/default/default/template/sales/order/view/items.phtml

Adding header for items to make it look like below:

<tr class="headings">
    <th><?php echo $this->helper('sales')->__('Product') ?></th>
    <th><?php echo $this->helper('sales')->__('Comments') ?></th>
    <th><?php echo $this->helper('sales')->__('Item Status') ?></th>

Adding Column with comments. app/design/adminhtml/default/default/template/sales/order/view/items/renderer/default.phtml
Add a column for item comments juts before status columns to make it look a like below

<td><?php echo $this->getItemcomment($_item) ?></td> <!-- New column added for item comments -->
<td class="a-center"><?php echo $_item->getStatus() ?></td>