Compare form domain with database domain

Question

I need to compare domain sent and processed by a form via $_POST with domains of the database because I can only enter one email from each domain in the database. For this first I took the email from $_POST and then stored all the base emails in an array with mysql_fetch_array at the bank. Now, I need to get this array return only domains as I did with explode which resulted in variable $tmpdominio and then compare these two information to see if the domain already exists in the bank. As I am starting, so far I have this code.

# Pegando o dominio deste email
$emaildoform    = $_POST['email'];
$tmpdominio     = explode('@', $emaildoform);

# Pegando todos os emails da minha tabela
$dados      = mysql_query("SELECT email FROM wp_agencias");

while($arraydeemails = mysql_fetch_array($dados)){

    # Eu preciso extrair o domínio de cada e-mail do array ...
    # ... depois vou comparar com $tmpdominio para ...
    # ...verificar se dominio está presente na base

};

Answer 1

Perhaps the solution meets your need, then you will have a good idea of what can be done. Success!

if (isset($_POST['email'])){
   // Recuperando domínio do e-mail recebido pelo form
   $dominio = explode( '@', $_POST['email'] );

   // Pegando todos os emails da minha tabela
   $dados = mysql_query("SELECT email FROM wp_agencias WHERE email LIKE @".$dominio[1]);

if( $dados) {
   echo "Domínio ". $dominio[1]." já cadastrado";
} else {
   echo "Domínio ". $dominio[1]." não cadastrado";
}
}

Answer 2

// Extrai apenas o dominio do e-mail.
$dominio = explode('@', $_POST['email']);
$dominio = $dominio[1];

// Torna a string segura para uso em consultas.
// (Evita SQLInjection).
$dominio = mysql_real_escape_string($dominio);

// Consulta se o dominio já existe.
$dados = mysql_query('SELECT email FROM wp_agencias WHERE email LIKE "%@'.$dominio.'"');

if (mysql_num_rows($dados)>0) die("Dominio já existe");
else
{
    // Torna a string segura para uso em consultas.
    $email = mysql_real_escape_string($_POST['email']);

    // Insere no banco de dados.
    mysql_query('INSERT INTO wp_agencias(email) VALUES ("'.$email .'");');
}

Answer 3

First I would like to know if this mailing list is too big. If it is, it may give you performance problems. But I will talk about two options. If your list is small this gist here can help you solve:

<?php
class DomainCheck {
    private $email;

    function __construct($email_a_verificar) {
        $this->email = $email_a_verificar;
    }

    private function getDominio($email) {
        $email = explode('@',$email);
        return $email[ count( $email ) - 1 ];
    }

    function check($lista_de_emails) {
        $dominio_a_verificar = $this->getDominio( $this->email );

        foreach( $lista_de_emails['email'] as $email ) {
            $dominio_atual = $this->getDominio( $email );

            if ( $dominio_a_verificar == $dominio_atual ) {
                throw new Exception("Domínio existente na lista", 1);
            }
        }
    }
}

//a lista simula o seu recordset
//usando um fetchAll do PDO
$lista_emails_do_banco = array(
    'email'=>array(
        '[email protected]',
        '[email protected]',
        '[email protected]',
        '[email protected]',
        '[email protected]'
    )
);

$email_recebido_do_form = '[email protected]';

$check = new DomainCheck($email_recebido_do_form);
try {
    $check->check( $lista_emails_do_banco );
    echo "Sem duplicações de e-mail";
    //Rotina de salvamento do registro pode vir aqui
} catch( Exception $e ) {
    echo $e->getMessage();
}

https://gist.github.com/evaldobarbosa/c302b2d1c327a0708735

But if your list is muuuuuuuito large, then you can add a field for the domain in the table with the emails and then search for the domain field.