Question

I have a table with 3 columns (smallint) in SQL Server 2005.

Table Ratings
ratin1 smallint,
ratin2 smallint
ratin3 smallint

These columns can have values from 0 to 5.

How can I select the average value of these fields, but only compare fields where the value is greater then 0.

So if the column values are 1, 3 ,5 – the average has to be 3.
if the values are 0, 3, 5 – The average has to be 4.

Answer 1

This is kind of quick and dirty, but it will work…

SELECT (ratin1 + ratin2 + ratin3) / 
((CASE WHEN ratin1 = 0 THEN 0 ELSE 1 END) + 
(CASE WHEN ratin2 = 0 THEN 0 ELSE 1 END) + 
(CASE WHEN ratin3 = 0 THEN 0 ELSE 1 END) +
(CASE WHEN ratin1 = 0 AND ratin2 = 0 AND ratin3 = 0 THEN 1 ELSE 0 END) AS Average