On Mon, 14 Aug 2006 18:19:55 +0100, Thomas Mangin <[EMAIL PROTECTED]> wrote:
>
> you could as well do something like :
>
> # information stored about a person
>
> create table contact_info (
> contact_id int not null,
> contact_type int not null,
> /* more contact fields like before ??? */
> value text(255),
> primary key (contact_id,contact_type)
> )
>
> # Associate a the information with a roundcube user.
>
> create table contact (
> contact_id serial not null,
> owner_id int not null,
> contact_name text not null,
> primary_key (contact_id)
> )
>
> # Type of information stored
>
> create table types (
> type_id int not null,
> type_name text not null,
> primary key (type_id)
> )
>
> alter table contact_info add foreign key (contact_id) references contact
> (contact_id) on delete cascade on update cascade
> alter table contact_info add foreign key (contact_type) references types
> (type_id) on update cascade on delete cascade
>
> # Pseudo inserts to make sense of the tables.
>
> insert into contact (owner_id, contact_name) values (CONTACT_DAVID,
> 'Thomas Mangin'); # creates contact_id CONTACT_THOMAS
> insert into contact_info (contact_id, contact_type, value) values
> (CONTACT_THOMAS, TYPE_TELNO, '+44 1274 000000');
IMHO this is a better approch. The problem is, as Charles mentioned, any kind
of data would go in a VARCHAR(255) field, making it dificult to sort by dates
or so. I think that if a data type is a date, it should go in a date field, and
the same for integer, string, etc.
--
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Lic. Martín Marqués | SELECT 'mmarques' ||
Centro de Telemática | '@' || 'unl.edu.ar';
Universidad Nacional | DBA, Programador,
del Litoral | Administrador
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