Re: Table Relationships

On 10/31/06, A. Kretschmer <andreas(dot)kretschmer(at)schollglas(dot)com> wrote:
>
> am Tue, dem 31.10.2006, um 11:15:26 -0600 mailte Curtis Scheer folgendes:
> > Given the following two tables:
> >
> > CREATE TABLE public.task
> > (
> > taskid int4 NOT NULL DEFAULT nextval('task_taskid_seq'::regclass),
> > description varchar,
> > CONSTRAINT pk_taskid PRIMARY KEY (taskid)
> > )
> >
> > public.users
> > (
> > userid int4 NOT NULL,
> > username varchar,
> > CONSTRAINT pk_userid PRIMARY KEY (userid)
> > )
> >
> > I want to record which user ?performed the task? and which user ?checked
> the
> > task?, I?ve come up with a few ideas on this but I would like to know
> what the
> > correct way would be to implement this into my table design.
>
> Perhaps a table like this:
>
>
> (
> user int references public.users,
> task int references public.task,
> ts timestamptz default now(),
> action char(1) check (action in ('p','c'))
> )
>
>
> -- with p(perform), c(cheked)

I would go further by adding a type table like this:

operation_type (
operation_type_id bigserial (PK),
operation_cd varchar(10),
operation_name varchar(20)
)

with two codes "perform" and "check" and another table

operation (
user int references public.users (PK),
task int references public.task (PK),
ts timestamptz default now() (PK),
operation_type_id bigint references operation_type
)

This gives you the flexibility to add more operation types in the future.

==================================================================
Aaron Bono
Aranya Software Technologies, Inc.
http://www.aranya.com
http://codeelixir.com
==================================================================