uninstall.php

<?php

// If uninstall not called from WordPress exit.
if ( ! defined( 'WP_UNINSTALL_PLUGIN' ) ) {
	exit();
}

/**
 *    Uninstalls plugin (deletes options, metas and removes database table)
 */
function ppw_uninstall() {
	delete_option( 'ppw_options' );

	global $wpdb;
	$table = $wpdb->prefix . "pay_per_view";

	if ( $wpdb->get_var( "SHOW TABLES LIKE '" . $table . "'" ) == $table ) {
		$wpdb->query( "DROP TABLE " . $table );
	}

	$wpdb->query( "DELETE FROM " . $wpdb->usermeta . " WHERE meta_key='ppw_subscribe' OR meta_key='ppw_recurring' OR meta_key='ppw_days' " );
	$wpdb->query( "DELETE FROM " . $wpdb->postmeta . " WHERE meta_key='ppw_method' OR meta_key='ppw_enable' OR meta_key='ppw_excerpt' OR meta_key='ppw_price' " );
}
ppw_uninstall();