sql - how to get sum(col2) as somename,(col2*col3)/Sum(col2) as somename1 for the some date

Question

MY column:

col1    col2    col3    date
a         11    0    3/6/2015:0:00:00
b          5    4    3/6/2015:0:00:00
c          5    5    3/6/2015:0:00:00
d          3    0    3/6/2015:0:00:00
e         21    21   3/6/2015:0:00:00

O/P required :

col2(sum)   col2*col3/sum(col2)      date
   45               11              3/6/2015 0:00

Answer 1

I assume that you want to get the sum and ang for the dates

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