Question

Possible Duplicate:
insert contacts into database but does not want to duplicate already existing contact

Hello. I’m trying to check if an email already exists before I insert a duplicate.

So I need to check the database for the presence of the email address and if it exists ouput a message saying it already exists. Otherwise I want to insert the record into the database.

Here is the code I use to insert the email now, but I’m not sure how to check the database for existence.

$addEmailQuery  = sprintf("INSERT INTO `subscribe`(`Email`) VALUES('%s')",
                            mysql_real_escape_string($_POST['inputEmail']));
        $addEmailResult = mysql_query($addEmailQuery);
        if($addEmailResult){
            echo 'Email successfully submitted';

        } else{
            echo 'Sorry, we could not submit your email. Please try again.';
        }

Anyone know how I would do this?

Answer 1

EDITED:
The initial answer will pose problems in a multi-user environment.

You should do like

INSERT ... ON DUPLICATE KEY UPDATE

Follow this answer to get it correct.

ORIGINAL POST:

if(mysql_num_rows(mysql_query("SELECT * FROM subscribe WHERE Email = '".mysql_real_escape_string($_POST['inputEmail'])."'")))
{
     echo "already submitted";
}   
else
{

    $addEmailQuery  = sprintf("INSERT INTO `subscribe`(`Email`) VALUES('%s')",
                        mysql_real_escape_string($_POST['inputEmail']));
    $addEmailResult = mysql_query($addEmailQuery);
    if($addEmailResult)
    {
       echo 'Email successfully submitted';

     } 
     else
     {
        echo 'Sorry, we could not submit your email. Please try again.';
     }

}