CREATE TABLE strings (
 `id` int(5) NOT NULL AUTO_INCREMENT, // Идентификатор
 `name` varchar(100) DEFAULT NULL, // Наименование набора
 `lang` varchar(10) DEFAULT NULL, // Наименование локали
 `value` varchar(100) DEFAULT NULL, // Код строки
 `text` varchar(300) DEFAULT NULL, // Локализация
 `sorter` int(5) DEFAULT NULL, // Используется для сортировки в пределах локали
 `deleted` tinyint(1) DEFAULT '0', // Признак, что запись не активная
 PRIMARY KEY (`id`)
) DEFAULT CHARSET=utf8

INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'ru_ru', '001', 'Первый', 100, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'ru_ru', '002', 'Второй', 200, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'ru_ru', '003', 'Третий', 300, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'en_us', '001', 'First', 200, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'en_us', '002', 'Second', 100, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'de_de', '001', 'Erste', 10, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'de_de', '002', 'Zweite', 20, 0);
INSERT INTO strings (name, lang, value, text, sorter, deleted) VALUES('set1', 'de_de', '003', 'Dritte', 30, 0);

SELECT value, text  FROM strings WHERE lang ='ru_ru' AND name = 'set1' AND deleted = 0 ORDER BY sorter;

SELECT 
    a.value AS value,
    IFNULL(IFNULL(b.text, c.text), d.text) AS text
FROM
    (SELECT DISTINCT
        name, value
    FROM
        strings
    WHERE
        name = 'set1' AND deleted = 0) AS a
        LEFT JOIN
    strings b ON b.deleted = 0 AND b.name = a.name
        AND b.value = a.value
        AND b.lang = 'en_us'
        LEFT JOIN
    strings c ON c.deleted = 0 AND c.name = a.name
        AND c.value = a.value
        AND c.lang = 'ru_ru'
        LEFT JOIN
    strings d ON d.deleted = 0 AND d.name = a.name
        AND d.value = a.value
        AND d.lang != 'en_us'
        AND d.lang != 'ru_ru'
ORDER BY IFNULL(IFNULL(b.sorter, c.sorter), d.sorter)