Question

我已经尝试了以下php脚本来验证用户输入。但是表单被发送到数据库而没有提示用户填写必填字段，即如果用户将一个或多个字段留空，则提交表单而不要求填写字段。如何阻止它提交，直到满足每个表单字段的条件？

以下是代码： -

<?php
$fnameErr=$lnameErr=$emailErr=$passwordErr=$cpasswordErr="";
if ($_SERVER['REQUEST_METHOD'] === 'POST') 
{ 
   if(empty($_POST["fname"]))
     { 
      $fnameErr="First name is Required";
     }
  else
    {
    $fname = $_POST["fname"];
    }
    if (empty($_POST["lname"]))
    {
    $lnameErr = "Last Name is required";
    }
  else
    {
    $lname = $_POST["lname"];
    }
    if (empty($_POST["email"]))
    {
    $emailErr = "Email is required";
    }
  else
    {
    $email = $_POST["email"];
    }
    if (empty($_POST["password"]))
    {
    $passwordErr = "Password is required";
    }
  else
    {
    $password = $_POST["password"];
    }
    if (empty($_POST["cpassword"]))
    {
    $cpasswordErr = "Confirm Password";
    }
  else
    {
    $cpassword = $_POST["cpassword"];
    }

    //Create connection
$con=mysqli_connect("localhost","root","p11","daot");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }
    $sql="INSERT INTO registration (FirstName, LastName, EmailAddress,Password,ConfirmPassword)
VALUES
('$_POST[fname]','$_POST[lname]','$_POST[email]','$_POST[password]','$_POST[cpassword]')";

if (!mysqli_query($con,$sql))
  {
  die('Error: ' . mysqli_error($con));
  }
  mysqli_close($con);
}

?> 
<html>
<head>
<link rel="stylesheet" type="text/css" href="mastercss.css">
<title>SIGN UP PAGE</title>
</head>
<body>
<?php include 'header.php'; ?>
<div class="leftbar">
 </div>
<div class="content">
<h1 class="h1">complete the following form to register</h1>
<fieldset style="width:450px; background:gray;">
<form autocomplete="on" method="POST" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
  <label for="fname">First Name:</label>
  <input type="text" name="fname"><?php echo $fnameErr;?><br><br>
  <label for="lname">Last Name:</label>
  <input type="text" name="lname"><?php echo $lnameErr;?><br><br>
  <label for="email">Email:</label>
  <input type="email" name="email"><?php echo $emailErr;?><br><br>
  <label for="password">Password:</label>
  <input type="password" name="password"><?php echo $passwordErr;?><br><br>
  <label for="cpassword">Confirm Password</label>
  <input type="password" name="cpassword"><?php echo $cpasswordErr;?><br><br>
  <!--<label for="sex">Sex</label><input type="radio" name="sex" value="female"> Female
  <input type="radio" name="sex" value="male">Male<br>
  <label for="select">Birthday</label>
<select name="birthday_Month" id="month">
<option value="0" selected="1">Month</option>
<option value="1">January</option>
<option value="2">February</option>
<option value="3">March</option>
</select>
<select name="birthday_day" id="month">
<option value="0" selected="1">Day</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<select name="birthday_year" id="year">
<option value="0" selected="1">year</option>
<option value="2010">2010</option>
<option value="2011">2011</option>
<option value="2012">2012</option>
</select><br><br>-->
<input type="submit" value="SIGN UP" style="width:100: height:100" name="Submit">
</form>
</fieldset>
</div>
<div class="rightbar"><br><br>
<a href="https://www.twitter.com"><img src="tw1.jpg">
<a href="https://www.facebook.com"><img src="fb2.jpg"></a>
</div>
<?php include "footer.php";?>

</body>
</html>

Answer 1

提交表单时未显示验证，因为即使在执行验证条件后，它仍在执行以下代码行。如果从代码段退出任何验证不正确，则需要避免执行代码。

if(empty($_POST["fname"]))
     { 
      $fnameErr="First name is Required";
      exit;
     }

Answer 2

你应该这样做

if(empty($_POST["fname"]))
     { 
      $fnameErr="First name is Required";
      echo $fnameErr;
exit();
     }

其他条件

和相同。

Answer 3

这将立即显示所有错误：

在 PHP ：

中

$error = array(); //save all errors into one array, later we will check if this array is empty to proceed with saving into DB
if(empty($_POST["fname"]))
     { 
      $error['fname']="First name is Required";
     }
  else
    {
    $fname = $_POST["fname"];
    }
    if (empty($_POST["lname"]))
    {
    $error['lname'] = "Last Name is required";
    }
  else
    {
    $lname = $_POST["lname"];
    }
    if (empty($_POST["email"]))
    {
    $error['email'] = "Email is required";
    }
  else
    {
    $email = $_POST["email"];
    }
    if (empty($_POST["password"]))
    {
    $error['password'] = "Password is required";
    }
  else
    {
    $password = $_POST["password"];
    }
    if (empty($_POST["cpassword"]))
    {
    $error['cpassword'] = "Confirm Password";
    }
  else
    {
    $cpassword = $_POST["cpassword"];
    }

if (empty($errors)) {
//if there are no errors, save into DB
//Create connection
$con=mysqli_connect("localhost","root","p11","daot");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }
    $sql="INSERT INTO registration (FirstName, LastName, EmailAddress,Password,ConfirmPassword)
VALUES
('$_POST[fname]','$_POST[lname]','$_POST[email]','$_POST[password]','$_POST[cpassword]')";

if (!mysqli_query($con,$sql))
  {
  die('Error: ' . mysqli_error($con));
  }
  mysqli_close($con);
}
}

在您的 HTML ：

中

  <label for="fname">First Name:</label>
  //checking if error message is set, if yes display it
  <input type="text" name="fname"><?php echo isset($error['fname'])?$error['fname']:'' ;?><br><br>
  <label for="lname">Last Name:</label>
  <input type="text" name="lname"><?php echo isset($error['lname'])?$error['lname']:'' ;?><br><br>
  <label for="email">Email:</label>
  <input type="email" name="email"><?php echo isset($error['email'])?$error['email']:'' ;?><br><br>
  <label for="password">Password:</label>
  <input type="password" name="password"><?php echo isset($error['password'])?$error['password']:'' ;?><br><br>
  <label for="cpassword">Confirm Password</label>
  <input type="password" name="cpassword"><?php echo isset($error['cpassword'])?$error['cpassword']:'' ;?><br><br>

表单无需验证即可发送：php mysql

3 个答案: