Need help wording if statement

Okay, I'm running the following sql query

			$sql = " SELECT * FROM " . ADR_SHOPS_ITEMS_TABLE . "
				WHERE item_in_shop = 0
				AND item_in_warehouse = 0
				AND item_duration > 0
				AND item_owner_id = $user_id 
				AND item_type_use = 50 ";

			{
				message_die(GENERAL_ERROR, 'Could not query battle list', '', __LINE__, __FILE__, $sql);
			}
			$ammo = $db->sql_fetchrow($result);

PHP:

What I want to do is add some code like

if(no entries found for search)
{
post message
}

I know how to do the message, but I'm not sure how to write the if statement.

Could someone help please?

 

$sql = "[your sql statement here]";
$rst = mysql_query($sql);

if(mysql_num_rows($rst) > 0) {
  // code if found
}
else {
  // code if not found
}

Code (markup):

 

Thanks for the help