Calculating percentages with GROUP BY query

Question

I have a table with 3 columns which looks like this:

File    User     Rating (1-5)
------------------------------
00001    1        3
00002    1        4
000         


        

Answer 1

WITH data AS 
 (SELECT User, Rating, Count(*) AS Count 
  FROM Results
  GROUP BY User, Rating)
SELECT User, Rating, Count, 
       (0.0+n)/(SUM(Count) OVER (PARTITION BY User))
FROM data;