图像字段更新查询

Question

我在php中创建了一个上传和显示图像的表单... 我试图找出如何更新表中的blob字段，但它在这里不起作用的是代码

    $editFormAction = $_SERVER['PHP_SELF'];
if (isset($_SERVER['QUERY_STRING'])) {
  $editFormAction .= "?" . htmlentities($_SERVER['QUERY_STRING']);
}

if ((isset($_POST["MM_update"])) && ($_POST["MM_update"] == "form1")) {
  $updateSQL = sprintf("UPDATE product SET ProductName=%s, `Description`=%s, ProductPrice=%s, ProductPic=%s, PictureType=%s WHERE ProductID=%s",
                       GetSQLValueString($_POST['ProductName'], "text"),
                       GetSQLValueString($_POST['Description'], "text"),
                       GetSQLValueString($_POST['ProductPrice'], "double"),
                       GetSQLValueString($_POST['ProductPic'], "text"),
                       GetSQLValueString($_POST['PictureType'], "text"),
                       GetSQLValueString($_POST['ProductID'], "int"));

  mysql_select_db($database_dutyfree, $dutyfree);