insert into t1 values (128, 'rozn', 2, curdate(), 10),
(128, 'rozn', 1, curdate(), 10);
SELECT MIN(price) min, MAX(price) max, AVG(price) avg FROM (SELECT SUBSTRING( MAX(concat(date_,";",price)), 12) price FROM t1 WHERE itemid=128 AND grpid='rozn' GROUP BY itemid, grpid, vendor) lastprices;