我的登錄表單中有一些問題，如何解決？

Question

我輸入了信息，然后單擊“提交查詢”進行登錄，它會將我重定向到空白頁面 。

• 我已經在嘗試登錄的信息中注冊了。

• 並在數據庫中檢查用戶是否存在。 這是代碼：

   <?php // ERROR DEBUG THINGY $showErrors = (isset($_GET['debug'])) ? true : false; if(!$showErrors) { ini_set('display_errors', 'Off'); } else { error_reporting(E_ALL); ini_set('display_errors', 'On'); } // DATABASE START $servername = "localhost"; $username = "root"; $conn = mysql_connect($servername, $username) or die (mysql_error()); mysql_select_db("test", $conn); // WE START THE SESSION session_start(); // START LOGIN PROCESS if(isset($_SESSION['logged'])) { print_secure_content(); //CONTENT THAT'S ECHOED ONCE YOU LOG IN } else { if(!$_SESSION['logging']) { //IF LOGGING SESSION ISNT RUNNING $_SESSION['logging'] = true; //RETURNS THE USER BACK TO THE LOGIN FORM loginform(); //SHOWS THE LOGIN FORM } else if($_SESSION['logging']) { $numberOfRows = checkpass(); //CHECK IF THE USER ALREADY EXISTS if($numberOfRows == 1) { //IF OLD USER LOG HIM IN $_SESSION['id'] = $_POST['username']; $_SESSION['logged'] = true; echo "<h1> You have logged in successfully </h1>"; print_secure_content(); print_user_details(); } else { echo "You have entered a wrong username or password, please try again.<br />"; loginform(); } } } // DATABASE CLOSE mysql_close(); // FUNCTIONS!!! function loginform() { //THE LOG IN FORM echo "Please login <br /> <form method=\\"POST\\" action=\\"?\\"> USERNAME<br /> <input name='username' type='text'><br /> PASSWORD<br /> <input name='password' type='password'><br /> <input type='submit' name='login'></form> <p><a href='registerform.php'> Register Here! </a></hr>"; } function print_user_details() { //CHECK PASSWORD if(isset($_POST['username']) && isset($_POST['password'])) { $sql = "SELECT * FROM users WHERE name = '{$_POST['username']}' and password = '{$_POST['password']}'"; $result = mysql_query($sql, $conn) or die (mysql_error()); return mysql_num_rows($result); } } function checkpass() { //CHECK PASSWORD if(isset($_POST['username']) && isset($_POST['password'])) { $sql = "SELECT * FROM users WHERE name = '{$_POST['username']}' and password = '{$_POST['password']}'"; $result = mysql_query($sql, $conn) or die (mysql_error()); return mysql_num_rows($result); } } function print_secure_content() { // ECHO ONCE YOU LOG IN echo 'Hello '. $_SESSION['id'] .'!<br />'; echo 'Only a logged in user can see this. <br /> <a href="logout.php"> Logout </a>'; } 

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Answer 1

可能存在某些語法錯誤。

轉到php.ini文件
將display_errors = off更改為on並保存。
重新啟動服務器
檢入前端。 您可能會發現錯誤。 改正它。
再次重新啟動服務器以查看您的更改。

Answer 2

$ sql =“ SELECT * FROM users where where name ='”。$ _ POST ['username']。“'and password ='”。$ _ POST ['password']。“”“;

像這樣的用戶sql查詢