Comment afficher 0 si champs est null Mysql

$query = " SELECT substr(customers_from, 1, 3) AS Origin,
       COUNT(DISTINCT cu.customers_id) AS effectif, ifnull( co.commandes_status , '0') ,count(co.commandes_status) AS command, 
       AVG(co.commandes_montant) AS Mmc 
FROM customers cu
INNER JOIN commandes co 
ON cu.customers_id=co.customers_id 
WHERE co.commandes_status='1'  
GROUP BY Origin ";

$query_vg ="
SELECT substr(customers_from, 1, 3) AS Origin, 
       COUNT(*) AS effectif_vg
FROM customers 

GROUP BY Origin ";
$result_vg = mysql_query($query_vg) ;



	// requete pour chaque ligne "client" (ayant une facture)
	$query = " SELECT substr(customers_from, 1, 3) AS Origin,
       COUNT(DISTINCT cu.customers_id) AS effectif ,count(co.commandes_status) AS command, 
       AVG(co.commandes_montant) AS Mmc 
FROM customers cu
INNER JOIN commandes co 
ON cu.customers_id=co.customers_id 
WHERE co.commandes_status='1'  
GROUP BY Origin ";
	$result = mysql_query($query) ;
	
 


while ($row1 = mysql_fetch_array($result_vg) and $row = mysql_fetch_array($result) ) 
{
	if($row['command'] == '0' )
	{ $row['command'] .= 'zero';

?>
		<tr>
			<td style="background-color:#CCCCCC;">  </td>
            <td style="text-align:center;"> <?php echo $row1['Origin'] ?> </td>
			 <td style="text-align:center;"> <?php echo $row1['effectif_vg'] ?> </td>
			<td style="text-align:center;"> <?php echo $row['command'] ?> </td>
            <td style="text-align:center;"> <?php echo round(($row['command']*$row['Mmc'])) ?> euro</td>
              <td style="text-align:center;"> <?php echo round($row['Mmc'] ,2)?> </td>
		</tr>  
<?php
}  }	
?>

 co.commandes_status='1'

$query_produit = 
					" SELECT substr(customers_from, 1, 3) AS Origin,
					   COUNT(DISTINCT cu.customers_id) AS effectif, count(co.commandes_status) AS command,
					   AVG(co.commandes_montant) AS Mmc 
						FROM customers cu
						INNER JOIN commandes co  
						ON cu.customers_id=co.customers_id 
						WHERE co.commandes_status='1' 
						and  substr(customers_from , 1 , 3) ='".$row['Origin']."'
						AND customers_date_inscription BETWEEN '2009-04-01' AND '2009-04-30'
						GROUP BY Origin ";