php登錄始終挑選其他

Question

在我的登錄檢查頁面中，即使文本正確，它也會始終轉到else語句。

登錄頁

<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確認頁

<?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");} 
?> 

我到底做錯了什麼？

Answer 1

我認爲mysqli_num_rows($q);沒有返回1，嘗試轉儲它並查看此輸出，通過使用var_dump(mysqli_num_rows($q));或者它可能是它返回值超過1的情況，請嘗試用$numrows >= 1替換$numrows == 1。 它必須在任何情況下工作，如果您的數據庫工作正常！

Answer 2

我想你是不是通過正確的密碼/用戶名到數據庫，嘗試改變：

$q = mysqli_query("SELECT * FROM user WHERE username='$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()需要從mysqli_connect()$connection參數資源。

它必須是：

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

還建議：

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