How can i use validate my signup form in php - php

Question

I want to check all my signup fiels to be validate in php but it seems it not take other validation except email validation. Please have a look so that can help me to bug my errors.
Thank you.
Here its my signup process...
if($_POST['action']=="signup")
{
$name = mysqli_real_escape_string($connection,$_POST['name']);
$email = mysqli_real_escape_string($connection,$_POST['email']);
$bankid = mysqli_real_escape_string($connection,$_POST['bankid']);
$phone = mysqli_real_escape_string($connection,$_POST['phone']);
$password = mysqli_real_escape_string($connection,$_POST['password']);
$query = "SELECT email FROM users where email='".$email."'";
$result = mysqli_query($connection,$query);
$numResults = mysqli_num_rows($result);
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) // Validate email address
{
$message = "E - post Redan also!!";
}
elseif($numResults>=1)
{
$message = $email." E-post redan finns!!";
}
else
{
mysqli_query($connection,"insert into users(name,email,bankid,phone,password) values('".$name."','".$email."','".$bankid."','".$phone."','".md5($password)."')");
$message = "Registrera framgångsrikt!!";
}
}

Answer 1

If I understand you correctly, you want to be able to validate all the fields of your sign up form on submit, correct?
There are various examples online of using filter_var in PHP - a bit of Googling will get you the answers.
I would recommend using a validation library that's built to help you make sure your code is secure. An example of such library is: https://github.com/Wixel/GUMP
If you have a look at the source code for GUMP, there are more examples using filter_var:
https://github.com/Wixel/GUMP/blob/master/gump.class.php#L878
filter_var($value, FILTER_SANITIZE_NUMBER_INT)
filter_var($value, FILTER_SANITIZE_SPECIAL_CHARS);
// etc