一直在看這個好幾天，不知道。 「警告：mysql_num_rows（）期望參數1是資源，布爾給出

Question

好吧，所以我想添加一個用戶註冊表單到我的網站。我一直試圖解決這個問題好幾天沒有我已經試過似乎在工作的時候填寫登記表目前我得到這個警告並點擊提交按鈕

警告：。mysql_num_rows（）預計參數1是資源，在/應用空給出/ XAMPP/xamppfiles/htdocs目錄/tutorials/MySite/index.php on line 64

我有三重檢查，以確保我的數據庫和行的語法在腳本和phpmyadmin中是相同的，所以我真的失去了，沒有從這裏知道該怎麼做，我總是遇到連接和做查詢的麻煩s /從phpmyadmin中檢索信息。

到目前爲止，這是我已經得到了（對不起了這麼多的代碼）：

<?php 

$reg = $_POST['reg']; 
// declaring variables to prevent errors 

$fn  = ""; //first name 
$ln  = ""; //last name 
$un  = ""; //username 
$em  = ""; //email 
$em2  = ""; //email 2 
$pswd = ""; //sign up date 
$u_check = ""; //check if username exists 

//registration form 
$fn = strip_tags($_POST['fname']); 
$ln = strip_tags($_POST['lname']); 
$un = strip_tags($_POST['username']); 
$em = strip_tags($_POST['email']); 
$em2 = strip_tags($_POST['email2']); 
$pswd = strip_tags($_POST['password']); 
$pswd2 = strip_tags($_POST['password2']); 
$d  = date("Y-m-d"); // year - month - day 

if ($reg) { 
    if ($em == $em2) { //this block of code is where I'm having the most trouble at. 
     // Check if user already exists 
     $u_check = mysql_query("'SELECT' username 'FROM' users 'WHERE' username='$un'"); 
     // Count the amount of rows where username= $un 
     $check = mysql_num_rows($u_check); //<<<<<<<<<<<<<<<<<<<<<<<<LINE 64 
     if ($check == 0) { //maybe this should be $u_check??\\ 




      //check all of the fileds have been filled in 
      if ($fn && $ln && $un && $em && $em2 && $pswd && $pswd2) { 
       //check that passwords match 
       if ($pswd == $pswd2) { 
        //check the maximum length of username/first name/last name does not exceed 25 characters. 
        if (strlen($un) > 25 || strlen($fn) > 25 || strlen($ln) > 25) { 
         echo "The maximum limit for username/first name/ last name is 25 characters!"; 

        } else { //check to see if password is allowable length 
         if (strlen($pswd) > 30 || strlen($pswd) < 5) { 
          echo "Your password must be between 5 and 30 characthers long!"; 
         } else { 
          //encrypts password using md5 before sending to database 
          $pswd = md5($pswd); 
          $pswd2 = md5($pswd2); 
          $query = mysql_query("INSERT INTO users VALUES (' ', '$un', '$fn', '$ln', '$em', '$pswd', '$d', '0')"); 
          die("<h2>Welcome to MySite</h2>Login to your account to get started...."); 
         } 
        } 
       } else { 
        echo "Your passwords don't match!"; 

       } 
      } else { 
       echo "Please fill in all fields"; 
      } 
     } 
    } 
} 

?> 

再次，我一直試圖讓這個固定的日子，但還是無法弄清楚什麼是繼續。

Answer 1

由於您的查詢未返回要計數的對象，您會收到錯誤消息。這是失敗的。

你的查詢有無效的語法：

$u_check = mysql_query ("'SELECT' username 'FROM' users 'WHERE' username='$un'"); 

應該是：

$u_check = mysql_query ("SELECT `username` FROM `users` WHERE `username`='$un'"); 

而且對人類的愛淨化你的輸入，並切換到PDO或mysqli看到，因爲mysql_功能已被棄用

這是一個非常基本的PDO示例，它假定您遵循基本教程連接到您的數據庫：

//assumes $db is your PDO connection 
$sql = $db->prepare('SELECT `username` FROM `users` WHERE `username`=:username'); 
$sql->bindParam(':username', $un, PDO::PARAM_STR); 
$sql->execute(); 

Answer 2

使用PDO

$sql= "SELECT `username` FROM `users` WHERE `username` = :username"; 
$stmt = $pdo->prepare($sql); 
$stmt->bindParam(':username', $un, PDO::PARAM_STR); 
$stmt->execute();