SELECT supplier_ID,
CONCAT(SUM(IF(`date`='2012-01-01',ROUND(Price,2),NULL)), '(', SUM(IF(`date`='2012-01-01',QTY,NULL)), ')') AS '2012-01-01',
CONCAT(SUM(IF(`date`='2012-01-03',ROUND(Price,2),NULL)), '(', SUM(IF(`date`='2012-01-03',QTY,NULL)), ')') AS '2012-01-03',
CONCAT(SUM(IF(`date`='2012-05-01',ROUND(Price,2),NULL)), '(', SUM(IF(`date`='2012-05-01',QTY,NULL)), ')') AS '2012-05-01'
FROM supplier
GROUP BY supplier_ID