Question

我需要使用php显示错误消息。我正在解释下面的代码。

addcomplain.php：

<div style="color:#F00; text-align:center;"><?php echo $error?></div>
<form name="billdata" id="billdata"  enctype="multipart/form-data" method="POST" onSubmit="javascript:return checkForm();" action="complain.php">
</form>

假设我有一个上面的表格，当我提交下面的文件时会被调用。

complain.php：

$sql="SELECT * FROM medilink_complain WHERE email='".$email."'";
$selres = mysqli_query($con,$sql);
 if(mysqli_num_rows($selres ) > 0)
   {
    $error = "Email Id already exists!";

    }

当上述错误发生时，我需要它应该显示在表单上方。在我的情况下，我没有得到任何东西。请帮我解决这个问题。

Answer 1

试试这个

addcomplain.php：

<?php 
if(isset($_SESSION["error"])){
    echo '<div style="color:#F00; text-align:center;">'. $_SESSION["error"] .'</div>';;
    unset($_SESSION["error"]);
} ?>

complain.php：

session_start();
$sql="SELECT * FROM medilink_complain WHERE email='".$email."'";
$selres = mysqli_query($con,$sql);
 if(mysqli_num_rows($selres ) > 0)
   {
        $_SESSION["error"] = "Email Id already exists!";
   }

Answer 2

您不需要会话。

将代码合并为1个文件。如果他不为，则仅显示$error，如下所示：

<?php
   $error = null;

   if ($_SERVER['REQUEST_METHOD'] == 'POST') {
       $sql="SELECT * FROM medilink_complain WHERE email='".$email."'";
       $selres = mysqli_query($con,$sql);

       if(mysqli_num_rows($selres ) > 0) {
           $error = "Email Id already exists!";
       }
    }

?>

<div style="color:#F00; text-align:center;"><?= (!is_null($error) ? $error : ''); ?></div>
     <form name="billdata" id="billdata"  enctype="multipart/form-data" method="POST" onSubmit="javascript:return checkForm();" action="complain.php">
     </form>
</div>

Answer 3

试试这样：

complain.php：

$sql="SELECT * FROM medilink_complain WHERE email='".$email."'";
$selres = mysqli_query($con,$sql);
 if(mysqli_num_rows($selres ) > 0)
   {
    $_SESSION["error"] = "Email Id already exists!";

    }

在addcomplain.php中：

$error = $_SESSION["error"];
unset($_SESSION["error"]);
    <div style="color:#F00; text-align:center;"><?php echo $error?></div>
    <form name="billdata" id="billdata"  enctype="multipart/form-data" method="POST" onSubmit="javascript:return checkForm();" action="complain.php">
    </form>

Answer 4

您可以编写几个函数来简化：

function setMessage($message){
    $_SESSION['msg'] = $message;
}

function showMessage(){
    echo $_SESSION['msg'];
    unset($_SESSION['msg']);
}

complain.php：

if(mysqli_num_rows($selres ) > 0)
{
    $error = "Email Id already exists!";
    setMessage($error);
}

addcomplain.php：

<div style="color:#F00; text-align:center;"><?php echo showMessage(); ?></div>

注意：请确保您已使用页面顶部的session_start()启动了会话。

Answer 5

使用Session对象。

$sql="SELECT * FROM medilink_complain WHERE email='".$email."'";
$selres = mysqli_query($con,$sql);

if(mysqli_num_rows($selres ) > 0)
{
    $_SESSION['error'] = "Email Id already exists!";

}

这样的显示。

<?php 
    $error = "";
    if(isset($_SESSION['error'])) 
    { 
        $error = $_SESSION['error']; 
        unset($_SESSION['error']); 
    } 
  ?>
  <div style="color:#F00; text-align:center;">
      <?php echo $error; ?>
  </div>

  <form name="billdata" id="billdata"  enctype="multipart/form-data" method="POST" onSubmit="javascript:return checkForm();" action="complain.php">
  </form>

Answer 6

complain.php

    <?php
    $sql="SELECT * FROM medilink_complain WHERE email='".$email."'";
    $selres = mysqli_query($con,$sql);
    if(mysqli_num_rows($selres ) > 0)
    {
       $error = "Email Id already exists!";
    } else {
       $error = '';
    }
    include 'addcomplain.php'; // <----
    ?>

addcomplain.php

    <html>
    <body>    
    <div style="color:#F00; text-align:center;"><?php echo $error?></div>
    <form name="billdata" id="billdata"  enctype="multipart/form-data" method="POST" onSubmit="javascript:return checkForm();" action="complain.php">
    <input value="test" />
    </form>    
    </body>
    </html>

......对我有用！不需要会话变量。

如何使用PHP在视图页面中显示错误消息

6 个答案:

complain.php

addcomplain.php