source: code-engine/trunk/uninstall.php

<?php
if ( !defined( 'WP_UNINSTALL_PLUGIN' ) ) {
    die;
}

function mwcode_remove_database() {
        global $wpdb;
        $table_name1 = $wpdb->prefix . "mwcode_snippets";
        $sql = "DROP TABLE IF EXISTS $table_name1";
        $wpdb->query( $sql );

        
}

function mwcode_remove_options() {

        // Delete the options
        $option_functions = 'mwcode_functions';
    $option_intervals = 'mwcode_intervals';
        $options = 'mwcode_options';

        delete_option( $options );
        delete_option( $option_functions );
        delete_option( $option_intervals );
}

function mwcode_uninstall () {
        $options = get_option( 'mwcode_options' );
        $cleanUninstall = array_key_exists( 'clean_uninstall', $options ) ? $options['clean_uninstall'] : false;

        if ( $cleanUninstall ) {
                mwcode_remove_options();
                mwcode_remove_database();
        }

}

mwcode_uninstall();