Eu suponho que você deseja obter a soma e ang para as datas
SELECT sum(col2) AS sum
,CASE
WHEN sum(col2 * col3) = 0
THEN 0
ELSE sum(col2 * col3) / sum(col2) AS avg
,DATE GROUP BY DATE
SELECT sum(col2) AS sum
,CASE
WHEN sum(col2 * col3) = 0
THEN 0
ELSE sum(col2 * col3) / sum(col2) AS avg
,DATE GROUP BY DATE