出现此错误。请任何人帮忙。我是这方面的初学者。
Undefined variable: mysqli in C:\xampp\htdocs\final\register.php on line 20
Fatal error: Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\final\register.php:20 Stack trace: #0 {main}
thrown in C:\xampp\htdocs\final\register.php on line 20
我们需要做什么才能通过一些验证来验证 html 表单，以及如何将提交的详细信息放入数据库表中？
这是代码
注册.php
<?php
include "header.php";
// Include config file
require_once 'dbconfig.php';
// Define variables and initialize with empty values
$username = $password = $confirm_password = "";
$username_err = $password_err = $confirm_password_err = "";
// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){
// Validate username
if(empty(trim($_POST["username"]))){
$username_err = "Please enter a username.";
} else{
// Prepare a select statement
$sql = "SELECT id FROM signup WHERE username = ?";
if($stmt = $mysqli->prepare($conn,$sql)){
// Bind variables to the prepared statement as parameters
$stmt->bind_param("s", $param_username);
// Set parameters
$param_username = trim($_POST["username"]);
// Attempt to execute the prepared statement
if($stmt->execute()){
// store result
$stmt->store_result();
if($stmt->num_rows == 1){
$username_err = "This username is already taken.";
} else{
$username = trim($_POST["username"]);
}
} else{
echo "Oops! Something went wrong. Please try again later.";
}
}
// Close statement
$stmt->close();
}
// Validate password
if(empty(trim($_POST['password']))){
$password_err = "Please enter a password.";
} elseif(strlen(trim($_POST['password'])) < 6){
$password_err = "Password must have atleast 6 characters.";
} else{
$password = trim($_POST['password']);
}
// Validate confirm password
if(empty(trim($_POST["confirm_password"]))){
$confirm_password_err = 'Please confirm password.';
} else{
$confirm_password = trim($_POST['confirm_password']);
if($password != $confirm_password){
$confirm_password_err = 'Password did not match.';
}
}
// Check input errors before inserting in database
if(empty($username_err) && empty($password_err) && empty($confirm_password_err)){
// Prepare an insert statement
$sql = "INSERT INTO signup (username, password) VALUES (?, ?)";
if($stmt = $mysqli->prepare($sql)){
// Bind variables to the prepared statement as parameters
$stmt->bind_param("ss", $param_username, $param_password);
// Set parameters
$param_username = $username;
$param_password = password_hash($password, PASSWORD_DEFAULT); // Creates a password hash
// Attempt to execute the prepared statement
if($stmt->execute()){
// Redirect to login page
header("location: login.php");
} else{
echo "Something went wrong. Please try again later.";
}
}
// Close statement
$stmt->close();
}
// Close connection
$mysqli->close();
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Sign Up</title>
<link rel="stylesheet"
href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; }
.wrapper{
width: 350px;
padding: 20px;
margin: 10px 10px 10px 10px;
}
</style>
</head>
<body>
<div class="jumbotron">
<div class="wrapper">
<h2>Sign Up</h2>
<p>Please fill this form to create an account.</p>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
<label>Username</label>
<input type="text" name="username"class="form-control" value="<?php echo $username; ?>">
<span class="help-block"><?php echo $username_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
<label>Password</label>
<input type="password" name="password" class="form-control" value="<?php echo $password; ?>">
<span class="help-block"><?php echo $password_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($confirm_password_err)) ? 'has-error' : ''; ?>">
<label>Confirm Password</label>
<input type="password" name="confirm_password" class="form-control" value="<?php echo $confirm_password; ?>">
<span class="help-block"><?php echo $confirm_password_err; ?></span>
</div>
<div class="form-group">
<input type="submit" class="btn btn-primary" value="Submit">
<input type="reset" class="btn btn-default" value="Reset">
</div>
<p>Already have an account? <a href="login.php">Login here</a>.</p>
</form>
</div>
</div>
</body>
</html>
if($stmt = mysqli_prepare($conn, $sql)){}
该行显示错误。什么是绑定(bind)以及如何使用它？
登录.php
<?php
include 'header.php';
// Include config file
require_once 'dbconfig.php';
// Define variables and initialize with empty values
$username = $password = "";
$username_err = $password_err = "";
// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){
// Check if username is empty
if(empty(trim($_POST["username"]))){
$username_err = 'Please enter username.';
} else{
$username = trim($_POST["username"]);
}
// Check if password is empty
if(empty(trim($_POST['password']))){
$password_err = 'Please enter your password.';
} else{
$password = trim($_POST['password']);
}
// Validate credentials
if(empty($username_err) && empty($password_err)){
// Prepare a select statement
$sql = "SELECT Username, Password FROM login WHERE Username = ?";
if($stmt = mysqli_prepare($conn, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "a", $param_username);
// Set parameters
$param_username = $username;
// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Store result
mysqli_stmt_store_result($stmt);
// Check if username exists, if yes then verify password
if(mysqli_stmt_num_rows($stmt) == 1){
// Bind result variables
mysqli_stmt_bind_result($stmt, $username, $hashed_password);
if(mysqli_stmt_fetch($stmt)){
if(password_verify($password, $hashed_password)){
/* Password is correct, so start a new session and
save the username to the session */
session_start();
$_SESSION['username'] = $username;
header("location: welcome.php");
} else{
// Display an error message if password is not valid
$password_err = 'The password you entered was not valid.';
}
}
} else{
// Display an error message if username doesn't exist
$username_err = 'No account found with that username.';
}
} else{
echo "Oops! Something went wrong. Please try again later.";
}
}
// Close statement
mysqli_stmt_close($stmt);
}
// Close connection
mysqli_close($link);
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Login</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; }
.wrapper{ width: 350px; padding: 20px; }
</style>
</head>
<body>
<div class="wrapper">
<h2>Login</h2>
<p>Please fill in your credentials to login.</p>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
<label>Username</label>
<input type="text" name="username"class="form-control" value="<?php echo $username; ?>">
<span class="help-block"><?php echo $username_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
<label>Password</label>
<input type="password" name="password" class="form-control">
<span class="help-block"><?php echo $password_err; ?></span>
</div>
<div class="form-group">
<input type="submit" class="btn btn-primary" value="Login">
</div>
<p>Don't have an account? <a href="register.php">Sign up now</a>.</p>
</form>
</div>
</body>
</html>
register_val.php
<?php
require_once('dbconfig.php');
// function for email validation
function is_valid_email($email)
{
if (empty($email)) {
echo "Email is required.";
return false;
} else {
$email = test_input($email);
// check if e-mail address is well-formed
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
echo "Invalid email format.";
return false;
}
// now check if the mail is already registered
$slquery = "SELECT 2 FROM signup WHERE Email = '$email'";
$selectresult = mysql_query($slquery);
if(mysql_num_rows($selectresult)>0) {
echo 'This email already exists.';
return false;
}
// now returns the true- means you can proceed with this mail
return true;
}
// function for password verification
function is_valid_passwords($password,$confirm_password)
{
// Your validation code.
if (empty($password)) {
echo "Password is required.";
return false;
}
else if ($password != $confirm_password) {
// error matching passwords
echo 'Your passwords do not match. Please type carefully.';
return false;
}
// passwords match
return true;
}
// function for creating user
function create_user($email, $password, $confirm_passwordpassword)
{
$query = "INSERT INTO `singup` (email, password, confirmpassword) VALUES ('$email', '$password', '$cpassword')";
$result = mysql_query($query);
if($result){
return true; // Success
}else{
return false; // Error somewhere
}
}
// Code execution starts here when submit
if (isset($_POST['email']) && isset($_POST['password'])){
// Reading form values
$email = $_POST['email'];
$password = $_POST['password'];
$confirm_password = $_POST['confirmpassword'];
if (is_valid_email($email) && is_valid_passwords($password,$confirm_password))
{
if (create_user($email, $password, $cpassword)) {
echo 'New User Registered Successfully.';
}else{
echo 'Error Registering User!';
}
}
// You don't need to write another 'else' since this is the end of PHP code
?>
dbconfig.php
<?php
$servername = "localhost";
$username = "root";
$password = "";
try {
$conn = new PDO("mysql:host=$servername; dbname = 'car sale' ", $username, $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e)
{
echo "Connection failed: " . $e->getMessage();
}
?>
最佳答案
你创建了对象$mysqli吗？
$mysqli = new Mysqli("host","db user","db password","db name");
在调用$mysqli之前将其放在Register.php上
关于PHP、MySQl 查询未运行，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49503471/