Re: Passing multiple rows to a function?

On Sun, Apr 24, 2005 at 03:00:55AM +0300, Vitaly Belman wrote:
>
> I know that you can pass rows/records to a function but what about a
> few rows? Is that possible?
>
> For example, I'd like to send to a function a number of rows from the
> "workers" table (e.g "select * from workers where age<10") and the
> function will return their summed salary.

See "Aggregate Functions" in the PostgreSQL Tutorial, and again in
the "Functions and Operators" chapter.  Here are links to documentation
for the latest version of PostgreSQL:

http://www.postgresql.org/docs/8.0/interactive/tutorial-agg.html
http://www.postgresql.org/docs/8.0/interactive/functions-aggregate.html

If you want to create your own aggregate functions, see "User-Defined
Aggregates" in the "Extending SQL" chapter and the documentation
for CREATE AGGREGATE:

http://www.postgresql.org/docs/8.0/interactive/xaggr.html
http://www.postgresql.org/docs/8.0/interactive/sql-createaggregate.html

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/