如何检查表单中的任何字段是否为空 [英] How to check if any fields in a form are empty

问题描述

我正在为我的网站构建一个登录系统，我需要一种检查表单中所有字段是否填写完毕的方法。

 <？php $ b我也有一个错误消息的问题，说我的电子邮件不是正确的格式。 $ b $ con = mysql_connect（localhost，262096，9201999）; 
 if（！$ con）
 {
 die（'Could not connect：'。mysql_error（））; 
} 
 mysql_select_db（262096，$ con）; 
 $ firstname = $ _POST ['firstname']; 
 $ lastname = $ _POST ['lastname']; 
 $ username = $ _POST ['username']; 
 $ password = $ _POST ['password']; 
 $ passwordconf = $ _POST ['passwordconf']; 
 $ email = $ _POST ['email']; 
 $ securityq = $ _POST ['securityq']; 
 $ qanswer = $ _POST ['qanswer']; 
 
 if（empty（$ firstname）|| empty（$ lastname）|| empty（$ username）|| empty（$ password）|| 
 empty（$ passwordconf）|| empty （$ email）|| empty（$ securityq）|| empty（$ qanswer））
 {
 echo你没有填写必填字段。 
 
 
 $ uname =SELECT * FROM users WHERE username ='{$ username}'; 
 $ unamequery = mysql_query（$ uname）或die（mysql_error（））; 
 if（mysql_num_rows（$ unamequery）> 0）
 {
 echo您输入的用户名已被占用; 
 
 
 $ emailfind =SELECT * FROM users WHERE email ='{$ email}'; 
 $ emailquery = mysql_query（$ emailfind）或die（mysql_error（））; 
 if（mysql_num_rows（$ emailquery）> 0）
 {
 echo您输入的电子邮件已被注册; 
 
 $ b $ if（$ password！= $ passwordconf）
 {
 echo输入的密码不匹配; 
} 
 
 $ regex =/^[a-z0-9]+([_.-][a-z0-9]+)*@([a-z0- 9] +（[.-] [A-Z0-9] +）*）+ [AZ] {2，} $ / I。 
 if（！preg_match（$ regex，$ email））
 {
 echo您输入的电子邮件地址不是名称@域格式; 
 
  

解决方案

使用表单字段创建一个数组：

$ $ p $ $ $ c $ $ field = array（'firstname'，'lastname'，'username'，'密码'，'passwordconf'，'email'，'securityq'，'qanswer'）;

$ error = false; //没有错误
foreach（$ fields AS $ fieldname）{//循环遍历每个字段
if（！isset（$ _ POST [$ fieldname]）|| empty（$ _ POST [$ fieldname] ））{
echo'Field'。$ fieldname。'missses！< br />>'; //显示字段错误
$ error = true; //有错误
}
}

if（！$ error）{//仅当没有错误发生时才创建查询
//创建查询.. ..
}

I am building a login system for a website of mine and I need a way of checking if all the fields in a form are filled out. I am also having a problem with an error message say my email is not in the correct format.

<?php
$con = mysql_connect(localhost, 262096, 9201999);
if (!$con)
{
    die('Could not connect: ' . mysql_error());
}
mysql_select_db("262096", $con);
$firstname = $_POST['firstname'];
$lastname = $_POST['lastname'];
$username = $_POST['username'];
$password = $_POST['password'];
$passwordconf = $_POST['passwordconf'];
$email = $_POST['email'];
$securityq = $_POST['securityq'];
$qanswer = $_POST['qanswer'];

if(empty($firstname) || empty($lastname) || empty($username) || empty($password) ||
    empty($passwordconf) || empty($email) || empty($securityq) || empty($qanswer))
{
    echo "You did not fill out the required fields.";
}

$uname = "SELECT * FROM users WHERE username='{$username}'";
$unamequery = mysql_query($uname) or die(mysql_error());
if(mysql_num_rows($unamequery) > 0) 
{
    echo "The username you entered is already taken";
}

$emailfind = "SELECT * FROM users WHERE email='{$email}'";
$emailquery = mysql_query($emailfind) or die(mysql_error());
if(mysql_num_rows($emailquery) > 0)
{
    echo "The email you entered is already registered";
}

if($password != $passwordconf)
{
    echo "The passwords you entered do not match";
}

$regex = "/^[a-z0-9]+([_.-][a-z0-9]+)*@([a-z0-9]+([.-][a-z0-9]+)*)+.[a-z]{2,}$/i";
if(!preg_match($regex, $email))
{
    echo "The email you entered is not in name@domain format";
}

解决方案

When using large forms I recommend creating an array with the form fields:

$fields = array('firstname', 'lastname', 'username', 'password', 'passwordconf', 'email', 'securityq', 'qanswer');

$error = false; //No errors yet
foreach($fields AS $fieldname) { //Loop trough each field
  if(!isset($_POST[$fieldname]) || empty($_POST[$fieldname])) {
    echo 'Field '.$fieldname.' misses!<br />'; //Display error with field
    $error = true; //Yup there are errors
  }
}

if(!$error) { //Only create queries when no error occurs
  //Create queries....
}

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