php登录始终挑选其他

Question

在我的登录检查页面中，即使文本正确，它也会始终转到else语句。

登录页

<form method="post" action="login.php"> 
<input type="text" placeholder="username" name="username"><br> 
<input type="password" placeholder="password" name="password"><br> 
<input type="submit" value="Submit"></form> 
</body> 
</html> 

loginin确认页

<?php 
session_start(); 
//connect to database 
include("db.php"); 

$username = $_POST["username"]; 
$password = $_POST["password"]; 
$q = mysqli_query("SELECT * FROM user WHERE username='$username' AND password='$password' "); 
//row count 
$numrows = mysqli_num_rows($q); 
if($numrows == 1){ 
while($rows = mysqli_fetch_assoc($q)){ 
$_SESSION["username"] = $row["username"]; 
$_SESSION["password"] = $row["password"];}header("location:check.php");} 
//always going to this else statement 
else 
{header("location:wrong.php");} 
?> 

我到底做错了什么？

Answer 1

我认为mysqli_num_rows($q);没有返回1，尝试转储它并查看此输出，通过使用var_dump(mysqli_num_rows($q));或者它可能是它返回值超过1的情况，请尝试用$numrows >= 1替换$numrows == 1。 它必须在任何情况下工作，如果您的数据库工作正常！

Answer 2

我想你是不是通过正确的密码/用户名到数据库，尝试改变：

$q = mysqli_query("SELECT * FROM user WHERE username='$username' AND password='$password' "); 

由：

$q = mysqli_query("SELECT * FROM user WHERE username='" . $username . "' AND password='".$password."' "); 

Answer 3

$q = mysqli_query("SELECT * FROM user WHERE username='$username' AND password='$password' "); 

mysqli_query()需要从mysqli_connect()$connection参数资源。

它必须是：

$q = mysqli_query($connection,"SELECT * FROM user WHERE username='$username' AND password='$password' "); 

还建议：

$numrows = mysqli_num_rows($q); 
if($numrows > 0) { 
// ... 
}