Question

我试图查找用户输入的用户名是否已被其他人使用过，但它似乎无法正常工作。这是代码。我不知道还能放什么。

   require 'database.php';

   $password = $_POST['password'];
   $fname = $_POST['fname'];
   $lname = $_POST['lname'];
   $username = $_POST['username'];
   $email = $_POST['email'];

   $message = '';
   if ($password === ""){
       $message = "<div class='errormsg'>Oops! Must've missed a spot!</div>";
   }
   else if ($fname === ""){
       $message = "<div class='errormsg'>Oops! Must've missed a spot!</div>";
   }
   else if ($lname === ""){
       $message = "<div class='errormsg'>Oops! Must've missed a spot!</div>";
   }
   else if ($email === ""){
       $message = "<div class='errormsg'>Oops! Must've missed a spot!</div>";
   }
   else if ($username === ""){
       $message = "<div class='errormsg'>Oops! Must've missed a spot!</div>";
   }
   $query = mysql_query("SELECT username FROM users WHERE username='".$username."'");

   if (mysql_num_rows($query) != 0)
   {
       $message = "<div class='errormsg'>Username already exists!</div>";
   }

Answer 1

尝试使用此功能检查具有该名称的现有用户：

function userExists($input) {
  $count = mysql_query("SELECT COUNT(*) FROM users WHERE username='".$input."'");
  if ($count > 0) $output = "User already exists";
  return $output;
}

您可以尝试这样检查：

if (userExists($username)) { ... }

但请考虑将来停止使用mysql_，因为它已被弃用。

试图查找用户名是否已被使用

1 个答案: