检查电子邮件是唯一的PHP

Question

I am creating a website about music and at the bottom of my website I have a form that has only email submission. I am doing this in order to gather email from the users.

Moreover, I have created a database and in that database I have created a table called emails with only 2 columns:idand email.

I would like to make the emails that I receive unique, because now that I am testing it I can put many emails with the same name. I have tried some coding in order to achieve this but no luck so I will post only the code I have at the moment, so you can help me with what I need to add in that code in order to receive a unique email address.

P.S I will update my database from mysql to mysqli at the end of the project.

Here is my current code:

<?php 
error_reporting(E_ERROR | E_PARSE);
include('../database/db.php');
$email = $_POST['email'];

if($email != "") {
$sql = mysql_query ("INSERT INTO emails (email) VALUES ('$email')");
echo "Thank you for Submitting. Redirecting back to Home Page";
}
?>

Answer 1

error_reporting(E_ERROR | E_PARSE);
include('../database/db.php');
$email = $_POST['email'];
if($email != "") {
    $result = mysql_query("SELECT * FROM emails where email='".$email."'");
    $num_rows = mysql_num_rows($result);
    if($num_rows >= 1){
        echo "email exist";
    }else{
        $sql = mysql_query ("INSERT INTO emails (email) VALUES ('$email')");
        echo "Thank you for Submitting. Redirecting back to Home Page";
    }
}

replace your code with this :)