我想从 sql 数据库中选择一些行。第一个用户应该插入两个变量，我可以选择这些行。然后在此页面中有一个表将更新此行，但问题是当我选择没有输入的这些列时，我可以更新数据库，但是当我想使用输入变量时，它会显示表但无法更新它。我在哪里做错了？
选择数据库列而不使用输入：
<?php
include 'mytool.php';
// username and password sent from form
$myusername=$_SESSION["mys"];
$host="localhost"; // Host name
$username='username'; // Mysql username
$password='password'; // Mysql password
$db_name="db"; // Database name
$tbl_name="test"; // Table name
// Connect to server and select database.
$link=mysql_connect($host,$username,$password)or die("cannot connect");
$selected=mysql_select_db($db_name,$link)or die("cannot select DB");
$sql="SELECT * FROM $tbl_name where classnum='106' and level='i4' ";
$result=mysql_query($sql,$link);
$count=mysql_num_rows($result);
?>
输入变量：
<form id="searchform" method="post" dir="rtl" action="">
level :<input name="level" type="text" id="level" />
classnumber :<input name="classnum" type="text" id="classnum" />
<input style="margin-top:10px; margin-left:120px; font-size: 14px; padding: 5px 14px;" type="submit" value="search" name="enter" />
</form>
<?php
if(isset($_POST['enter'])){
$sql="SELECT * FROM $tbl_name where classnum='106' and level='i4' ";
$result=mysql_query($sql,$link);
$count=mysql_num_rows($result);
}
?>
在上面的代码之后更新表代码：
<form name="form1" action="" method="POST">
<center>
<div>
<div align="center" width = 615>
<table class="stats" cellspacing="0" width="615" border="1">
<tr>
<th width="20" scope="col" >Id</th>
<th width="60" scope="col">Name</th>
<th width="60" scope="col">Last Name</th>
<th width="42" scope="col">Midterm</th>
<th width="54" scope="col">Class mark</th>
<th width="42" scope="col">Final Quiz</th>
<th width="54" scope="col">State</th>
<th width="54" scope="col">Details</th>
</tr>
<?php
while($rows=mysql_fetch_array($result)){
$id[]=$rows['id'];
?>
<tr>
<td align="center">
<input name="id[]" type="text" id="id" value="<? echo $rows['id']; ?>" >
</td>
<td align="center"><input type="text" name="name[]" id="name" value= "<? echo $rows['name']; ?>" /></td>
<td align="center"><input type="text" name="lastname[]" id="lastname" value= "<? echo $rows['lastname']; ?>" /></td>
<td align="center"><input type="text" name="midmark[]" id="midmark" /></td>
<td align="center"><input type="text" name="classmark[]" id="classmark" /></td>
<td align="center"><input type="text" name="finalmark[]" id="finalmark" /></td>
<td align="center"><input type="text" name="state[]" id="state" /></td>
<td align="center"><input type="text" name="details[]" id="details" /></td>
</tr>
<?php
}
?>
</table>
</div>
<input type="submit" value="ثبت" name="Submit" />
</form>
<?php
// Check if button name "Submit" is active, do this
if(isset($_POST['Submit']))
{
for($i=0;$i<$count;$i++)
{
$sql1=mysql_query(" UPDATE `".$tbl_name."` SET midmark='".$_REQUEST['midmark'][$i]."' , classmark='".$_REQUEST['classmark'][$i]."' , finalmark='".$_REQUEST['finalmark'][$i]."' , state='".$_REQUEST['state'][$i]."' , details='".$_REQUEST['details'][$i]."' WHERE id='".$_REQUEST['id'][$i]."' ");
$result1=mysql_query($sql1);
}
}
if($result1){
header("location:results.php");
}
mysql_close();
?>