theme-mods-functions.php

function element_transport_theme_mods() {
	global $wpdb;

	$themedata = $wpdb->get_var($wpdb->prepare("SELECT option_value FROM $wpdb->options WHERE option_name = %s", 'element'));
	if ($themedata) {
		$wpdb->update(
			$wpdb->options, // table
			array( 'option_value' => $themedata ), // column => data
			array( 'option_name' => 'elementchild' ) // where column
		);
	}

	$thememods = $wpdb->get_var($wpdb->prepare("SELECT option_value FROM $wpdb->options WHERE option_name = %s", 'theme_mods_element'));
	if ($thememods) {
		$wpdb->update(
			$wpdb->options, // table
			array( 'option_value' => $thememods ), // column => data
			array( 'option_name' => 'theme_mods_element-child' ) // where column
		);
	}

}
add_action ('after_setup_theme', 'element_transport_theme_mods');