Form Checking? [help]

[Macemore]

I have a E-Mail subscription form on my site, and I'd like to know how to keep people from entering the same E-Mail more than once, or from just entering any other E-Mail. (so they can only enter once)
How can I do this? (In php?)

 

[Markshall]

Are you using MySQL/i to store the emails in?

 

[Macemore]

Are you using MySQL/i to store the emails in?

No I don't know how to do that, I want to but Idk how.

 

[Markshall]

What are you using to store the emails?

 

[Macemore]

Absolutely nothing, it just emails their email to me.
lol.

 

[Alam]

You should have variables on top regarding you should also have a $query variable that will request data to your database so just do mysql_num_rows($query) if they query is used again the data will not insert to database.

 

[Macemore]

You should have variables on top regarding you should also have a $query variable that will request data to your database so just do mysql_num_rows($query) if they query is used again the data will not insert to database.

could you help me with that? I know nothing about SQL and so little aboot php.

 

[Markshall]

Well since you're not storing the email addresses and just having them sent to you, there is no possible way of checking against previous records of email addresses to see if it already exists.

 

[Kaz]

Your best off storing them in a mysql database, and once a person clicks submit (on the form) you need to make it to check if an entry already exists.
If it does exist then it will return them with an error, if it doesnt then their email will be inserted into the database

 

[Markshall]

You can set the database up yourself, but I'll start you off on a little checking system.

It should work, I coded it in the post box here. As I said, create the database yourself and change the MySQL details and table/column details.

<?php
mysql_connect( "localhost", "user", "pass" ) or die( mysql_error() );
mysql_select_db( "dbname" ) or die( mysql_error() );
 
if ( isset( $_POST["submit"] ) )
{
    $email = strip_tags( $_POST["email"] );
    $error = array();
 
    if ( empty( $error ) ) $error[] = 'Please enter an email address.';
    if ( !filter_var( $email, FILTER_VALIDATE_EMAIL ) ) $error[] = 'Please enter a valid email address.';
    if ( mysql_num_rows( mysql_query( "SELECT * FROM `EmailTable` WHERE `EmailAddress` = '" . mysql_real_escape_string( addslashes( $email ) ) . "'" ) ) > 0 ) $error[] = 'This email address has already been used.';
 
    if ( !empty( $error ) )
    {
        echo '<ul>';
        foreach ( $error as $v ) { echo '<li>' . $v . '</li>'; }
        echo '</ul>';
    }
    else
    {
        @mysql_query( "INSERT INTO `EmailTable` (`EmailAddress`, `IPAddress`) VALUES ('" . $email . "', '" . $_SERVER['REMOTE_ADDR'] . "')" );
        mail( "[email protected]", "subject", "message", "From: {$email}" );
    }
}
else
{
    echo '<form method="post" action="' . $_SERVER["PHP_SELF"] . '">
    <label for="email">Email Address:</label> <input type="text" name="email" id="email" value="" /><br />
    <input type="submit" name="submit" value="Go" />
    </form>';
}
?>

 

[Macemore]

You can set the database up yourself, but I'll start you off on a little checking system.

It should work, I coded it in the post box here. As I said, create the database yourself and change the MySQL details and table/column details.

<?php
mysql_connect( "localhost", "user", "pass" ) or die( mysql_error() );
mysql_select_db( "dbname" ) or die( mysql_error() );
 
if ( isset( $_POST["submit"] ) )
{
    $email = strip_tags( $_POST["email"] );
    $error = array();
 
    if ( empty( $error ) ) $error[] = 'Please enter an email address.';
    if ( !filter_var( $email, FILTER_VALIDATE_EMAIL ) ) $error[] = 'Please enter a valid email address.';
    if ( mysql_num_rows( mysql_query( "SELECT * FROM `EmailTable` WHERE `EmailAddress` = '" . mysql_real_escape_string( addslashes( $email ) ) . "'" ) ) > 0 ) $error[] = 'This email address has already been used.';
 
    if ( !empty( $error ) )
    {
        echo '<ul>';
        foreach ( $error as $v ) { echo '<li>' . $v . '</li>'; }
        echo '</ul>';
    }
    else
    {
        mail( "[email protected]", "subject", "message", "From: {$email}" );
    }
}
else
{
    echo '<form method="post" action="' . $_SERVER["PHP_SELF"] . '">
    <label for="email">Email Address:</label> <input type="text" name="email" id="email" value="" /><br />
    <input type="submit" name="submit" value="Go" />
    </form>';
}
?>

Thanks!

 

[Markshall]

Thanks!

Edited my previous post. I forgot to add the code to insert the email into the database once it has been sent.