这是html表单（register.php）：
<html>
<body>
<form action="handle_registration.php" method="post">
<fieldset><legend>Enter your
information in the form below:</legend>
First Name: <input type="text" name="fname" size="20" maxlength="40"><br>
Last Name: <input type="text" name="lname" size="20" maxlength="40"><br>
Username: <input type="text" name="uname" size="20" maxlength="40"><br>
Password: <input type="text" name="pword" size="20" maxlength="40"><br>
<input type="submit" name="submit" value="submit my info">
</form>
</body>
</html>
这是处理注册的php脚本（handle_registration.php）：
<?php
// Create a shorthand for the form data:
$fname = $_POST['fname'];
$lname = $_POST['lname'];
$uname = $_POST['uname'];
$pword = $_POST['pword'];
// Create the connection variables:
$db_host = "localhost";
$db_user = "root";
$db_pass = "";
$db_name = "registration_info";
$con = mysqli_connect("$db_host", "$db_user", "$db_pass", "$db_name");
// Check the connection:
if (mysqli_connect_errno ())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// Make sure all of the input boxes have a value:
if (empty($fname)) {
die('You forgot to enter your first name!');
}
if (empty($lname)) {
die('You forgot to enter your last name!');
}
if (empty($uname)) {
die('You forgot to choose a username!');
}
if (empty($pword)) {
die('You forgot to choose a password!');
}
// Insert the data from the form into the DB:
$sql = "INSERT INTO basic_information (First_Name, Last_Name, Username, Password)
VALUES
('$_POST[fname]', '$_POST[lname]', '$_POST[uname]', '$_POST[pword]')";
// Enter the info the end user type if everything is ok:
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
else
{
echo "Record has been added";
}
// Close the connection:
mysqli_close($con);
?>
问题是：
如果所有输入字段都有值，我想将输入的值提交到我的数据库中，但当我在检查它们是否为空后使用die函数时，它会杀死脚本。如果一个或多个字段为空，我只想杀死它插入到我的数据库中的部分；显示一条错误消息，告诉哪个字段为空。我不知道该如何度过难关，我们将不胜感激。
解决方案相当简单。只需将错误消息存储在一个变量中，在将行插入DB之前，请检查错误是否已设置或是否为空。如果它是空的，我们可以插入行。否则，让我们显示错误消息。
// Currently we do not have an error
$error = NULL;
// Validate
if (empty($pword)) {
$error = 'You forgot to choose a password!';
}
// If there are no errors - lets insert
if (!$error) {
$sql = 'INSERT INTO ...';
}
不要使用die，使用一些变量来存储错误，并在之后打印它们
<?php
// Create a shorthand for the form data:
$fname = $_POST['fname']; $lname = $_POST['lname']; $uname =
$_POST['uname']; $pword = $_POST['pword'];
// Create the connection variables:
$db_host = "localhost"; $db_user = "root"; $db_pass = ""; $db_name =
"registration_info"; $con = mysqli_connect("$db_host", "$db_user",
"$db_pass", "$db_name");
// Check the connection:
if (mysqli_connect_errno ()) { echo "Failed to connect to MySQL: " .
mysqli_connect_error(); }
// Make sure all of the input boxes have a value:
if (empty($fname)) { $error_msg[]='You forgot to enter your first name!'; }
if (empty($lname)) { $error_msg[]='You forgot to enter your last name!'; }
if (empty($uname)) { $error_msg[]='You forgot to choose a username!'; }
if (empty($pword)) { $error_msg[]='You forgot to choose a password!'; }
// Insert the data from the form into the DB:
if(count($error_msg)==0){
$sql = "INSERT INTO basic_information (First_Name, Last_Name,
Username, Password) VALUES ('$_POST[fname]', '$_POST[lname]',
'$_POST[uname]', '$_POST[pword]')";
// Enter the info the end user type if everything is ok:
if (!mysqli_query($con,$sql)) { die('Error: ' . mysqli_error($con)); }
else { echo "Record has been added"; }
// Close the connection:
mysqli_close($con);
}else{
print_r($error_msg);
}
?>
停止插入空数据的完整工作示例
<?php
if (isset($_POST["submit"])) {
$emptyInput = NULL;
if (!($_POST["firstname"] == $emptyInput or $_POST["lastname"] == $emptyInput or $_POST["email"] == $emptyInput)) {
$sql = "INSERT INTO MyGuests (firstname, lastname, email) VALUES ('" . $_POST["firstname"] . "','" . $_POST["lastname"] . "','" . $_POST["email"] . "')";
if (mysqli_query($conn, $sql)) {
echo 'Record inserted successfully!';
}
} else {
echo 'all fields are compulsory!';
}
}
?>
您可以使用$errors变量来保存所有字段的错误
$error = array();//initializing the $error
if (empty($fname)) {
$error[] = 'You forgot to enter your first name!';
}
if (empty($lname)) {
$error[] = 'You forgot to enter your last name!';
}
if (empty($uname)) {
$error[] = 'You forgot to choose a username!';
}
if (empty($pword)) {
$error[] = 'You forgot to choose a password!';
}
if(!empty($error))//if error occured
{
die(implode('<br />', $error));//Stops the script and prints the errors if any occured
}
// Insert the data from the form into the DB:
$sql = "INSERT INTO basic_information (First_Name, Last_Name, Username, Password)
VALUES
('$_POST[fname]', '$_POST[lname]', '$_POST[uname]', '$_POST[pword]')";
// Enter the info the end user type if everything is ok:
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
else
{
echo "Record has been added";
}
// Close the connection:
mysqli_close($con);