Question

我想在我的php中下载。

这意味着，我将有2个下拉列表。第一个下拉列表：小吃和小吃，饮料，洗浴用品第二个下拉列表：基于第一个下拉列表中的类别的不同子类别。

我想得到的结果是什么当我选择First first下拉列表，并选择snack＆amp; tibits时，在第二个下拉列表中，它将仅显示与snack＆amp; amp;相关的子类别。其他的2，等等，等等。

我试了一下，但是当我尝试检索第二个下拉列表时，它总是空白的。有人能告诉我如何改进我的代码？

谢谢

 <td width="175">Category:</td>
 <td width="405">

 <label>
 <select name="category_sel" id="category_sel" required="required" >
   <?php
do {  
?>
   <option value="<?php echo $row_sup_cat['category']?>"><?php echo $row_sup_cat['category']?></option>
   <?php
} while ($row_sup_cat = mysql_fetch_assoc($sup_cat));
  $rows = mysql_num_rows($sup_cat);
  if($rows > 0) {
      mysql_data_seek($sup_cat, 0);
      $row_sup_cat = mysql_fetch_assoc($sup_cat);
  }
?>
 </select>
 </label>



  </tr>
 <tr>

 <td>Subcategory:</td>
 <td>
<select name="subcatgory" id="subcatgory" required="required" >
  <?php
do {  
?>
  <option value="<?php echo $row_sup_subcat['subcategory']?>"><?php echo $row_sup_subcat['subcategory']?></option>
  <?php
} while ($row_sup_subcat = mysql_fetch_assoc($sup_subcat));
  $rows = mysql_num_rows($sup_subcat);
  if($rows > 0) {
      mysql_data_seek($sup_subcat, 0);
      $row_sup_subcat = mysql_fetch_assoc($sup_subcat);
  }
?>
</select>

 </td>
  </tr>

...

  <?php
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "") 
{
  if (PHP_VERSION < 6) {
    $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
  }

  $theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

  switch ($theType) {
    case "text":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;    
    case "long":
    case "int":
      $theValue = ($theValue != "") ? intval($theValue) : "NULL";
      break;
    case "double":
      $theValue = ($theValue != "") ? doubleval($theValue) : "NULL";
      break;
    case "date":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "defined":
      $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
      break;
  }
  return $theValue;
}
}

if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "") 
{
  if (PHP_VERSION < 6) {
    $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
  }

  $theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

  switch ($theType) {
    case "text":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;    
    case "long":
    case "int":
      $theValue = ($theValue != "") ? intval($theValue) : "NULL";
      break;
    case "double":
      $theValue = ($theValue != "") ? doubleval($theValue) : "NULL";
      break;
    case "date":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "defined":
      $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
      break;
  }
  return $theValue;
}
}

mysql_select_db($database_MyDatabase, $MyDatabase);
$query_sup_cat = "SELECT DISTINCT category FROM supermarket";
$sup_cat = mysql_query($query_sup_cat, $MyDatabase) or die(mysql_error());
$row_sup_cat = mysql_fetch_assoc($sup_cat);
$totalRows_sup_cat = mysql_num_rows($sup_cat);
$query_sup_cat = "SELECT DISTINCT category FROM supermarket";
$sup_cat = mysql_query($query_sup_cat, $MyDatabase) or die(mysql_error());
$row_sup_cat = mysql_fetch_assoc($sup_cat);
$totalRows_sup_cat = mysql_num_rows($sup_cat);

$colname_sup_subcat = "-1";
if (isset($_POST['category_sel'])) {
  $colname_sup_subcat = $_POST['category_sel'];
}
mysql_select_db($database_MyDatabase, $MyDatabase);
$query_sup_subcat = sprintf("SELECT subcategory FROM supermarket WHERE subcategory = %s", GetSQLValueString($colname_sup_subcat, "text"));
$sup_subcat = mysql_query($query_sup_subcat, $MyDatabase) or die(mysql_error());
$row_sup_subcat = mysql_fetch_assoc($sup_subcat);
$totalRows_sup_subcat = mysql_num_rows($sup_subcat);



?>

dropdownlist，显示基于第一个下拉列表php的第二个下拉列表

0 个答案: