ivapbox

Вот что еще накопал:

CREATE TRIGGER `update_test` AFTER INSERT ON `_test`
FOR EACH ROW BEGIN
  SET @iid = (SELECT value FROM _test ORDER BY id DESC LIMIT 1);
  SET @filepath = CONCAT(@iid, '.csv');
  SELECT *
          FROM _test
          ORDER BY id
          DESC LIMIT 1
          INTO OUTFILE @filepath

          CHARACTER SET cp1251 FIELDS TERMINATED BY ';' ENCLOSED BY '' LINES TERMINATED BY '\n';

END;

Создание переменной @filepath. Но я что-то упускаю:
[42000][1064] You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@filepath CHARACTER SET cp1251 FIELDS TERMINATED BY ';' ENCLOSED BY '' at line 9