即使所有輸入都正確，PHP代碼仍然顯示錯誤。我的代碼有什麼問題？

Question

我在php中做了一個簡單的註冊系統，即使我輸入了所有正確的細節，它也沒有進入數據庫，即使所有條目都正確，它仍然會回顯withError = 1。這是我的PHP代碼。

<?php 
if($submit) 
{ 
    if ($fullname && $email && $username && $password && $conPassword) 
    { 
     if(preg_match("/^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/", $email)) 
     { 
      $query1 = "SELECT Email FROM tbl_userAccounts WHERE Email='$email'"; 
      $result1 = mysqli_query($mysqli,$query1) or die(mysqli_error()); 
      if (mysqli_num_rows($result1) < 0) 
      echo "email is already used. "; 
      $withError = true; 
     } 
     else 
     { 
      echo "invalid email address. "; 
      $withError = true; 
     } 
     if (strlen($username) < $charMinimum) 
     { 
      echo "minimum of 6 characters for username. "; 
      $withError = true; 
     } 
     else 
     { 
      $query2 = "SELECT Username FROM tbl_userAccounts WHERE Username='$username'"; 
      $result2 = mysqli_query($mysqli,$query2) or die(mysqli_error()); 
      if (mysqli_num_rows($result2) < 0) 
      { 
       echo "username is already used. "; 
       $withError = true; 
      } 
     } 
     if($password == $conPassword) 
     { 
      echo $withError; 
      if($withError == false) 
      { 
       if (strlen($password) < $charMinimum) 
       { 
        echo "minimum of 6 characters for password. "; 
        $withError = true; 
       } 
       else 
       { 
        $query3 = "INSERT INTO tbl_userAccounts VALUES ('', '$fullname', '$username', '$password','$date', '$email')"; 
        $result3 = mysqli_query($mysqli,$query3) or die(mysqli_error()); 
        if($result3 && $withError == false) 
        echo "account has been successfully registered!"; 
        else 
        echo "failed registration. "; 
       } 
      } 
     } 
     else 
     { 
      echo "passwords do not match. "; 
      $withError = true; 
     } 
    } 
} 
else 
{ 
    echo "fill out all fields. "; 
    $withError = true; 
} 
?> 

Answer 1

if (mysqli_num_rows($result1) < 0) 
{ 
    echo "email is already used. "; 
    $withError = true; 
} 

你忘了花括號

Answer 2

你忘了包裝嵌套的IF語句。

if(preg_match("/^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/", $email)) 
    { 
     $query1 = "SELECT Email FROM tbl_userAccounts WHERE Email='$email'"; 
     $result1 = mysqli_query($mysqli,$query1) or die(mysqli_error()); 
     if (mysqli_num_rows($result1) < 0) { 
      echo "email is already used. "; 
      $withError = true; 
     } 
    }