Re: Merging multiple values into comma-delimited list in a view

Thanks for the solution, Bruno. I spent some time last night working
with aggregates and group by after being pointed in the right direction
by you and Bruce and was at the point where I could get the correct
rows with a count of how many email addresses a person had. I had also
written an aggregate function to concatenate the addresses, but was
stuck on how to make that actually work within the query. Thanks again;
I'll be integrating this into the data model for the app I'm building.

/s.

On Mar 4, 2004, at 1:15 AM, Bruno Wolff III wrote:

> drop view people_with_email;
> drop table people2email;
> drop table email;
> drop table people;
> drop aggregate concatenate(text);
> drop function join_with_comma(text,text);
>
> create function join_with_comma(text,text)
> returns text
> immutable strict language 'sql'
> as 'select $1||'', ''||$2'
> ;
>
> create aggregate concatenate (
> sfunc = join_with_comma,
> basetype = text,
> stype = text
> );
>
> create table email (
> email_id integer primary key,
> email_address text not null unique
> );
>
> copy email from stdin with delimiter '|';
> 1|scott(at)scottg(dot)tv
> 2|fred(dot)flintstone(at)blah(dot)com
> 3|barney(at)hodown(dot)com
> 4|barney(dot)rubble(at)hey(dot)org
> \.
>
> create table people (
> person_id integer primary key,
> first_name text not null,
> last_name text not null
> );
>
> copy people from stdin with delimiter '|';
> 1|Scott|Goodwin
> 2|Fred|Flintstone
> 3|Barney|Rubble
> \.
>
> create table people2email (
> person_id integer references people (person_id),
> email_id integer references email (email_id)
> );
>
> copy people2email from stdin with delimiter '|';
> 1|1
> 2|2
> 3|3
> 3|4
> \.
>
> create view people_with_email as
> select
> a.first_name,
> a.last_name,
> c.email_address
> from
> people a,
> (select r.person_id, concatenate(b.email_address) as
> email_address
> from people2email r, email b
> where r.email_id = b.email_id
> group by r.person_id) as c
> where a.person_id = c.person_id
> ;