Re: aggregate function

It is generally possible - but there is a limitation that makes the specific example fail.

You can write a function to do:

select f(col1, col2, col3), col1, col2,col3 from table
group by col1, col2, col3;

The function simply has to embed a

    select {requirements} from table
    where col1 = parm1
    and col2 = parm2
    and col3 = parm3

It seems to work quite efficiently as the function is called AFTER the group by,
i.e. just once for each combination of
col1, col2, col3.

--
Jonathan Lewis
Yet another Oracle-related web site:  http://www.jlcomp.demon.co.uk

Practical Oracle 8i:  Building Efficient Databases

Publishers:  Addison-Wesley
See a first review at:
http://www.ixora.com.au/resources/index.htm#practical_8i
More reviews at: http://www.jlcomp.demon.co.uk/book_rev.html



Alex Filonov wrote in message <91r5up$ldk$1_at_nnrp1.deja.com>...


>As far as I know, you can't.

>

>In article <91qgc1$16n$1_at_nnrp1.deja.com>,

>  slezakp_at_my-deja.com wrote:

>> Can one write an aggregate function in Oracle 8.1.6?

>>

>> Example:  normal sum

>>

>> select sum(tools) from powertools;

>>

>> I want to be able to do:

>>

>> select mysum(tools) from powertools.

>>

>> Note that mysum will not know what table or column ahead of time.

>>

>> Thanks,

>> Paul

>>

>> Sent via Deja.com

>> http://www.deja.com/

>>

>

>

>Sent via Deja.com

>http://www.deja.com/