สอบถามเรื่อง num_rows นะครับ ว่า datetime มัน num_rows ได้ไหมครับ หรือว่า มันจะ รวมกันยังไง....

$id = $_REQUEST['txtid'];
$startdatebill = $_GET['txtstart'];
$enddatebill = $_GET['txtend'];
$strSQL = "SELECT SUM(b.iMoney) AS IMONEY,
                  SUM(b.iQuantity) AS IQTY,
                  CONVERT(nvarchar, a.dDate,1)AS Imonths
                  FROM SaleBillVouch AS a RIGHT OUTER JOIN 
                  SaleBillVouchs AS b ON a.SBVID = b.SBVID
                  WHERE (a.dDate BETWEEN '$startdatebill' AND '$enddatebill') 
                  AND b.cInvCode = '$id'
                  GROUP BY CONVERT(nvarchar, a.dDate,1)
                  ORDER BY CONVERT(nvarchar, a.dDate,1)";
$objQuery = mssql_query($strSQL) or die ("Error Query [".$strSQL."]");

"SELECT 
MONTH(a.dDate) AS IMON,
YEAR(a.dDate) AS IYEAR,
SUM(b.iMoney) AS IMONEY,
SUM(b.iQuantity) AS IQTY
FROM SaleBillVouch AS a RIGHT OUTER JOIN 
SaleBillVouchs AS b ON a.SBVID = b.SBVID
WHERE (a.dDate BETWEEN '$startdatebill' AND '$enddatebill') 
AND b.cInvCode = '$id'
GROUP BY MONTH (a.dDate), YEAR (a.dDate)
";