Group by problem

[reek]

hey i have a table with two columns like

col1 col2
---- ----
1 2
1 2
1 4
2 5
2 8
3 7
2 8
4 6
2 5
3 7

what i wanna do is to
firstly calculate the mean of values of col2 on basis of col1 (grouped by col1). so i get a average for eeach of 1,2,3 and 4 from col1.
and then i wanna get the sum of those averages.

when i do
select sum(col2)/count(col2) from tablename group by col1;

i get all the averages collectly.

WHAT I NEED IS THE SUM OF THESE AVERAGES.

so i do
select sum(sum(col2)/count(col2)) from tablename group by col1;

but that gives error. whats the issue ??????? and how to get value desired ???? -- This message may have been cut off and the rest will only be shown to members. To become a member, click here --

[gerrard]

Here is your answer
Code

select sum(my_avg) as my_avg_sum
from (
select avg(col2) as my_avg
from tablename
group
by col1
) as d -- This message may have been cut off and the rest will only be shown to members. To become a member, click here --