How to check if data exists in SQL database ?

[abyssal]

Hello. I want to check if an e-mail address is stored into a database. I've found this type of code:

 

function verifmail($email)
{
    db_connect();
    if (mysql_num_rows(mysql_query("SELECT email FROM users WHERE email='$email';")))
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

 

Is it correct ? Is there any other way?

[Psycho]

Well, you can write it different ways, but the underlying process will be the same. You need to query the DB for existing records. I will say, however, that having an if/else statement that returns 1 or 0 is superfluous. Simply return the condition. Here is how I would write that:

 

//returns TRUE if email exists, else FALSE
function verifmail($email)
{
    db_connect();
    $email = mysql_real_escape_string($email);
    $query = "SELECT email FROM users WHERE email='$email' LIMIT 1";
    $result = mysql_query($query);
    return (mysql_num_rows($result)==1);
}