INNER JOIN กับการใช้ operator IN ไม่ออกครับ ทำอย่างไรดี

 instr (sale.sale_provinces,concat('''',provinces.PROVINCE_CODE,''''))

SELECT * FROM province, sale 
WHERE province.PROVINCE_NAME = '$query_province' 
	AND sale.sale_province LIKE concat('%''', province.province_code, '''%')


SELECT * FROM province, sale 
WHERE province.PROVINCE_NAME = '$query_province' 
	AND INSTR( sale.sale_province, concat('''', province.province_code, ''''))

<?
$sql_sale="SELECT * FROM sale WHERE username='".$_SESSION['log_username']."'";
$query_sale=mysql_query($sql_sale);
$result_sale=mysql_fetch_array($query_sale);
$result_provinces=$result_sale['sale_provinces'];

$sql_provinces="SELECT * FROM provinces WHERE PROVINCE_CODE IN ($result_provinces)";
$query_provinces=mysql_query($sql_provinces);
$num_provinces=mysql_num_rows($query_provinces);
?>

สวัสดีตัวแทนจำหน่าย  <?=$_SESSION['log_username']?> คุณได้รับมอบหมายให้ดูแลลูกค้าในจังหวัด  <b>

<?
if ($num_provinces<1) { echo "ไม่มี"; }else{
$i_provinces=0;
while ($i_provinces<$num_provinces) {
$result_provinces=mysql_fetch_array($query_provinces);
$keep_provinces[]=$result_provinces['PROVINCE_NAME'];
echo $result_provinces['PROVINCE_NAME'].",";
$i_provinces++; }}
?>