source: extensions/Media_Icon/install/functions.inc.php

<?php
function media_icon_install_general($config) {
        $query = 'INSERT INTO '.CONFIG_TABLE.' (param,value,comment) VALUES ("media_icon_general" ,"'.pwg_db_real_escape_string(serialize($config)).'", "Media Icon plugin general parameters");';
        pwg_query($query);
}

function media_icon_install_advanced($config) {
        $query = 'INSERT INTO '.CONFIG_TABLE.' (param,value,comment) VALUES ("media_icon_advanced" ,"'.pwg_db_real_escape_string(serialize($config)).'", "Media Icon plugin advanced parameters");';
        pwg_query($query);
}

function media_icon_update_db() {
        global $conf;
        include(dirname(__FILE__).'/config_default.inc.php');

        $config_general = array();
        $config_advanced = array();
        $conf_media_icon_general = unserialize($conf['media_icon_general']);
        $conf_media_icon_advanced = unserialize($conf['media_icon_advanced']);
        
        if (isset($conf['media_icon'])) {
                $query = 'DELETE FROM ' . CONFIG_TABLE . ' WHERE (param="media_icon");';
                pwg_query($query);
        }
        
        if (isset($conf_media_icon_general)) {
                foreach ($config_default_general as $key => $value) {
                        if (is_array($config_default_general[$key])) {
                                foreach ($config_default_general[$key] as $key2 => $value2) {
                                        if (is_array($config_default_general[$key][$key2])) {
                                                foreach ($config_default_general[$key][$key2] as $key3 => $value3) {
                                                        if (isset($conf_media_icon_general[$key][$key2][$key3]))
                                                                $config_general[$key][$key2][$key3] = $conf_media_icon_general[$key][$key2][$key3];
                                                        else
                                                                $config_general[$key][$key2][$key3] = $config_default_general[$key][$key2][$key3];
                                                }
                                        } else {
                                                if (isset($conf_media_icon_general[$key][$key2]))
                                                        $config_general[$key][$key2] = $conf_media_icon_general[$key][$key2];
                                                else
                                                        $config_general[$key][$key2] = $config_default_general[$key][$key2];
                                        }
                                }
                        } else {
                                if (isset($conf_media_icon_general[$key][$key2]))
                                        $config_general[$key] = $conf_media_icon_general[$key];
                                else
                                        $config_general[$key] = $config_default_general[$key];
                        }
                }
                media_icon_delete_conf("media_icon_general");
                media_icon_install_general($config_general);
        } else {
                media_icon_install_general($config_default_general);
        }
        
        if (isset($conf_media_icon_advanced)) {
                foreach ($config_default_advanced as $key => $value) {
                        if (isset($conf_media_icon_advanced[$key][$key2]))
                                $config_advanced[$key] = $conf_media_icon_advanced[$key];
                        else
                                $config_advanced[$key] = $config_default_advanced[$key];
                }
                media_icon_delete_conf("media_icon_advanced");
                media_icon_install_advanced($config_advanced);
        } else {
                media_icon_install_advanced($config_default_advanced);
        }
}

function media_icon_delete_conf($where) {
        $query = 'DELETE FROM ' . CONFIG_TABLE . ' WHERE (param="'.$where.'");';
        pwg_query($query);
}
?>