Re: Fwd: Re: Referencing

lucas(at)presserv(dot)org wrote:
> Quoting Daryl Richter <daryl(at)brandywine(dot)com>:
>
>> It's hard to say without knowing more precisely what you are trying to
>> model, but I think this push you in the right direction:
>>

[snipped old schema]

>
> Okay, but references between (output/input) and ACTIVITY tables is 1
to N.
> OUTPUT/INPUT - 1
> to
> ACTIVITY - N.
> And not N to 1 how the example.
> Then the reference field need to be on "ACTIVITY (send/buy)" table.
>

Ahh, ok. In that case I reverse it like so:

-- This table hold everything in common for inputs/outputs
create table transfer(
id serial primary key
);

create table output(
transfer_id int primary key references transfer,
client integer, --references clientes,
fiscal_number varchar(30),
print_date date
);

create table input(
transfer_id int primary key references transfer,
supplier integer, -- references suppliers,
employee varchar(30)
);

create table activity(
id serial primary key,
transfer_id int references transfer,
product_id integer, --references....
value money
);

create table financial(
id serial primary key,
cred_deb smallint,
value money,
activity_id integer references activity
);

create view buy
as
select
a.id as "input_id", -- or buy_id, etc. ...
b.supplier,
b.employee,
c.id as "activity_id",
c.product_id,
c.value
from
transfer a
join input b on b.transfer_id = a.id
join activity c on c.transfer_id = a.id;

If this is still not what you're after and you would like additional
assistance, it would really help to have at least a few rows of sample
data. Good luck!

--
Daryl Richter
Platform Author & Director of Technology

(( Brandywine Asset Management )
( "Expanding the Science of Global Investing" )
( http://www.brandywine.com ))