Pimcore\Tool::getFallbackLanguagesFor PHP Method

    public static function getFallbackLanguagesFor($language)
    {
        $languages = [];
        $conf = Config::getSystemConfig();
        if ($conf->general->fallbackLanguages && $conf->general->fallbackLanguages->{$language}) {
            $fallbackLanguages = explode(",", $conf->general->fallbackLanguages->{$language});
            foreach ($fallbackLanguages as $l) {
                if (self::isValidLanguage($l)) {
                    $languages[] = trim($l);
                }
            }
        }
        return $languages;
    }

    /**
     *
     */
    public function createLocalizedViews()
    {
        // init
        $languages = Tool::getValidLanguages();
        $defaultTable = 'object_query_' . $this->model->getClass()->getId();
        $db = $this->db;
        /**
         * macro for creating ifnull statement
         * @param string $field
         * @param array  $languages
         *
         * @return string
         */
        $getFallbackValue = function ($field, array $languages) use(&$getFallbackValue, $db) {
            // init
            $lang = array_shift($languages);
            // get fallback for current language
            $fallback = count($languages) > 0 ? $getFallbackValue($field, $languages) : 'null';
            // create query
            $sql = sprintf('ifnull(`%s`.`%s`, %s)', $lang, $field, $fallback);
            return $fallback !== 'null' ? $sql : $db->quoteIdentifier($lang) . '.' . $db->quoteIdentifier($field);
        };
        foreach ($languages as $language) {
            try {
                $tablename = $this->getQueryTableName() . "_" . $language;
                // get available columns
                $viewColumns = array_merge($this->db->fetchAll('SHOW COLUMNS FROM `' . $defaultTable . '`'), $this->db->fetchAll('SHOW COLUMNS FROM `objects`'));
                $localizedColumns = $this->db->fetchAll('SHOW COLUMNS FROM `' . $tablename . '`');
                // get view fields
                $viewFields = [];
                foreach ($viewColumns as $row) {
                    $viewFields[] = $this->db->quoteIdentifier($row['Field']);
                }
                // create fallback select
                $localizedFields = [];
                $fallbackLanguages = array_unique(Tool::getFallbackLanguagesFor($language));
                array_unshift($fallbackLanguages, $language);
                foreach ($localizedColumns as $row) {
                    $localizedFields[] = $getFallbackValue($row['Field'], $fallbackLanguages) . sprintf(' as "%s"', $row['Field']);
                }
                // create view select fields
                $selectViewFields = implode(',', array_merge($viewFields, $localizedFields));
                // create view
                $viewQuery = <<<QUERY
CREATE OR REPLACE VIEW `object_localized_{$this->model->getClass()->getId()}_{$language}` AS

SELECT {$selectViewFields}
FROM `{$defaultTable}`
    JOIN `objects`
        ON (`objects`.`o_id` = `{$defaultTable}`.`oo_id`)
QUERY;
                // join fallback languages
                foreach ($fallbackLanguages as $lang) {
                    $viewQuery .= <<<QUERY
LEFT JOIN {$this->getQueryTableName()}_{$lang} as {$lang}
    ON( 1
        AND {$defaultTable}.oo_id = {$lang}.ooo_id
    )
QUERY;
                }
                // execute
                $this->db->query($viewQuery);
            } catch (\Exception $e) {
                Logger::error($e);
            }
        }
    }