From: | "Aaron Bono" <postgresql(at)aranya(dot)com> |
---|---|
To: | "A(dot) Kretschmer" <andreas(dot)kretschmer(at)schollglas(dot)com> |
Cc: | pgsql-sql(at)postgresql(dot)org |
Subject: | Re: Table Relationships |
Date: | 2006-10-31 19:32:59 |
Message-ID: | bf05e51c0610311132w3bb1bb80i876750c9c5d8aee8@mail.gmail.com |
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Lists: | pgsql-sql |
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
==================================================================
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