how do i validate if my email is already exist? [closed] - php

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if(count($_POST)>0) { /* Form Required Field Validation / foreach($_POST as $key=>$value) {
if(empty($_POST[$key])) {
$message = ucwords($key) . " field is required"; break; } } / Password Matching Validation */
if($_POST['password'] != $_POST['confirm_password']){ $message = 'Passwords should be same '; }
/* Email Validation */ if(!isset($message)) { if (!filter_var($_POST["userEmail"], FILTER_VALIDATE_EMAIL)) { $message = "Invalid UserEmail"; }
}
/* Validation to check if gender is selected */ if(!isset($message)) { if(!isset($_POST["gender"])) { $message = " Gender field is required"; } }
if(!isset($message)) { require_once("dbcontroller.php"); $db_handle = new DBController();
$query = "INSERT INTO users (username, name, last_name, gender, BirthMonth, BirthDay, BirthYear, Country, email, password, phone) VALUES ('" . $_POST["userName"] . "', '" . $_POST["name"] . "', '" . $_POST["lastName"] . "', '" .$_POST["gender"] . "', '" . $_POST["BirthMonth"] . "', '" . $_POST["BirthDay"] . "' , '" . $_POST["BirthYear"] ."','". $_POST["Country"] ."', '" . $_POST["userEmail"]. "','" . $_POST["password"]. "','".$_POST["Phone"]. "')"; $result = $db_handle->insertQuery($query);
Edit: Format the code to visib;e errors better. Thanks in advance to anyone who answers.

Answer 1

you want to check that your email is exit in database then use this code. add this code after this line .
/* Email Validation */ if(!isset($message)) { if(!filter_var($_POST["userEmail"], FILTER_VALIDATE_EMAIL))
{ $message = "Invalid UserEmail"; }
}
your db connection need to connect for this so first connect this
require_once("dbcontroller.php"); $db_handle = new DBController();
hope your connection is ok so this code will check
<?php
$sql = "SELECT anyfiled FROM yourtable WHERE email = " .$_POST['userEmail'];
$select = mysqli_query($con, $sql);
$row = mysqli_fetch_assoc($select);
if (mysqli_num_rows($select) > 0) {
$message = "exist";
}
?>

Answer 2

Email Validation:
Apart from checking for common symbols like '#' and alpha-numeric, you must also check for white spaces/tabs in start and most importantly convert the incoming input using htmlspecialchars() as:
function reduceInput($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
Call the reduceInput() function on $_POST['userEmail'] and then use your filter_var() funciton to validate it.

Answer 3

I understand you mean not to pass exploiting strings to database? You don't have to validate these values for that. There is a php function which will pass the strings safely to your database. That's it:
mysqli_real_escape_string($mysqli_object, $_POST['userName']);
But if you'd like to validate your email and username, do this:
if (ctype_alnum($nick)==false) exit(0);// this makes your nick can only contain letters and numbers
$emailB = filter_var($email, FILTER_SANITIZE_EMAIL);//this sanitizes your email
if ((filter_var($emailB, FILTER_VALIDATE_EMAIL)==false) || ($emailB!=$email)) exit(0);//this validates your email