php - 我的 SQL 查询在查询中使用变量进行更新将不起作用

Question

 <form action="" method="POST">
 <h2>Event</h2>
 <br/>
 Update : <select name="updateevents"><option value="">New...</option>
 <?php $host="127.0.0.1"; 
 $user="belgiumca_db"; 
 $pw=""; 
 $db="belgiumca_db";

 $verbinding=mysql_connect($host,$user,$pw) or die("Kan de verbinding niet maken"); 
 mysql_select_db($db);

  $sql ="SELECT*FROM event";

 $result= mysql_query($sql);
 while($data = mysql_fetch_array($result))
 {
  echo "<option value='".$data['ID']."'>".base64_decode($data['eventitle'])."</option>";
 }
mysql_query($sql); 

 mysql_close($verbinding);
 ?>
 </select>
 &nbsp;<input name="load" type="submit" value="load">
 <br/>
 <?php
$update="false";
  if(isset($_POST['load']) && $_POST['updateevents'] !="")
   {
$update="true";

//设置$ident -->更新事件的内容(ID)

       $idevent=$_POST['updateevents'];
$host="127.0.0.1"; 
    $user="belgiumca_db"; 
    $pw=""; 
    $db="belgiumca_db";

    $verbinding=mysql_connect($host,$user,$pw) or die("Kan de verbinding niet maken"); 
    mysql_select_db($db);
    echo $idevent;
    $sql ="SELECT * 
    FROM  `event` 
    WHERE  `ID` ='".$idevent."'";
    $result= mysql_query($sql);
    while($data = mysql_fetch_array($result))
    {
  echo "<br/>Selected: ".$data['ID']." ".base64_decode($data['eventitle'])."<br/>";
  $eventtitle=base64_decode($data['eventitle']);
    }

 }
 ?>
 <br/>
 titel event: <input name="titleevent"   type="text" value="<?php echo $eventtitle; ?     >"   placeholder="Titel v/h event">
 <br/><br/><br/><br/>
 Text Event :<br/> <div id="txt"><textarea name="txtevent"   cols="100" rows="20"></textarea>   </div>
 <br/><br/><br/><br/>
 datum1 event: <input name="date1" id="datepicker"   type="text" placeholder="begindatum in    dag/maand/jaar"><br/><br/>datum2event : <input name="date2" id="datepicker" type="text" placeholder="begindatum in dag/maand/jaar">
 <br/><br/><br/><br/>
 photolink:
 <br/>
 <input   name="plink" type="text" placeholder="Photo link (bcc) voorlopig fb">
 <br/>
 videolink:
 <br/>
 <input   name="vlink" type="text" placeholder="Youtube link - video">
 <br/><br/><br/><br/>
 miniimagelink1:
<br/>
<input   name="miniimage1" type="text" placeholder="mini-image via facebook link hier">
<br/>
image preview:
<br/>
<img height="180" width="240" src="<?php echo $prevminiimg1;?>">
 <br/>
 miniimagelink2:
 <br/>
 <input   name="miniimage2" type="text" placeholder="mini-image via facebook link hier">
 <br/>
 image preview:
 <br/>
 <img height="180" width="240" src="<?php echo $prevminiimg2;?>">
 <br/>
  miniimagelink3:
  <br/>
   <input   name="miniimage3" type="text" placeholder="mini-image via facebook link hier">
   <br/>
   image preview:
   <br/>
   <img height="180" width="240" src="<?php echo $prevminiimg3;?>">
   <br/>
   miniimagelink4:
   <br/>
   <input   name="miniimage4" type="text" placeholder="mini-image via facebook link hier" >
   <br/>
   image preview:
   <br/>
   <img height="180" width="240" src="<?php echo $prevminiimg4;?>">
   <br/>
   <br/>
   Tags: <input name="tags" type="text" size="50">
   <br/>
   <input name="SAVE" type="submit" value="SAVE">
   </form>
   <?php 
   echo "id : ".$_POST['updateevents'];
   if(isset($_POST['SAVE']))
   {
    $id=$_POST['updateevents'];
if($_POST['date1'] != "" && $_POST['date2']!="")
{
     $eventdate=$_POST['date1']." - ".$_POST['date2'];  
}
else
{
    $eventdate=$_POST['date1'];
}
    $host="127.0.0.1"; 
    $user="belgiumca_db"; 
    $pw=""; 
    $db="belgiumca_db"; 

     $verbinding=mysql_connect($host,$user,$pw) or die("Kan de verbinding niet maken"); 
     mysql_select_db($db);

//更新查询

      $sql = "UPDATE `event`
      SET    `eventitle`='".base64_encode($_POST['titleevent'])."',`eventtxt`='".base64_encode($_POST['txtevent'])."',`eventdate`='".base64_encode($eventdate)."',`miniimage1`='".base64_encode($_POST['miniimage1'])."',`miniimage2`='".base64_encode($_POST['miniimage2'])."',`miniimage3`='".base64_encode($_POST['miniimage3'])."',`miniimage4`='".base64_encode($_POST['miniimage4'])."',`IP`='".$ipaddress."',`date`='".date('d-m-Y--H:i:s')."',`videolink`='".base64_encode($_POST['vlink'])."',`photolink`='".base64_encode($_POST['plink'])."',`tags`='".base64_encode($_POST['tags'])."' WHERE `ID`='".$id."'";
    echo $sql;
    mysql_query($sql) or die(mysql_error());
    mysql_close($verbinding);
   ?>`

//上面提到了完整的代码，希望你们中的任何人都可以解决这个问题，问题是我的 $id 或 $ideevent 无法在 SQL 查询中的 UPDATE 查询中使用

Answer 1

而不是这个

  mysql_query($sql);

使用

  mysql_query($sql) or die(mysql_error()); //to see whats wrong.

编辑:

我猜测您的变量 $id 未定义，这就是更新无法找到此 id 进行更新的原因。