Hi all,

Oracle 10.2 on linux ...

Is there any inbuilt way of calculating the average for values in separate
columns of a table across a row (cf. the average of values in rows for a
column) which allows for null values?

Given this data in table x:
row_id v1 v2 v3 v4
A 5 10 null 9
B null 5 5 null
C 6 8 7 7


I'd like a query result that looks like:
row_id row_avg
A 8 -- (5+10+9)/3
B 5 -- (5+5)/2
C 7 -- (6+8+7+7)/4

The simple math of (sum(v1 + v2 + v3 + v4) / 4) won't work due to null
addition, and nvl to sidestep this gives an incorrect denominator count.

Solution needs to be SQL not PL/SQL.

Yes, I know the data is poorly normalized.

GM