R4W

DROP TRIGGER IF EXISTS queue_log;
DELIMITER $$

CREATE TRIGGER `queue_log` AFTER insert ON `queue_log`
FOR EACH ROW BEGIN
  CASE NEW.`event` # не `queue_log`, а именно NEW
    WHEN 'COMPLETEAGENT' THEN UPDATE calls SET calls.laststep = 'answered' WHERE calls.uniqueid = NEW.callid;
    WHEN 'COMPLETECALLER' THEN UPDATE calls SET calls.laststep = 'answered' WHERE calls.uniqueid = NEW.callid;
    WHEN 'RINGNOANSWER' THEN DELETE FROM queue_log WHERE queue_log.callid = NEW.callid;
  END CASE;
END$$

DELIMITER ;