Re: INT OR VARCHAR

On Mié 05 Dic 2001 18:03, Aasmund Midttun Godal wrote:
> I am not sure what you are trying to do, but if you have a tree structure
> you will have to use an id column e.g.:
>
> CREATE TABLE domain (
>     id SERIAL PRIMARY KEY,
>     name TEXT CHECK (lower(name) ~ '[a-z0-9]([a-z0-9-]*[a-z0-9])?',
>     parent INTEGER REFERENCES domain,
>     UNIQUE (parent, name)
> );
>
>
> If you do not have a tree structure, I would recommend using a natural
> primary key in stead of serializing it. Bear in mind though - you should
> always have a primary key. I would also recommend creating a couple of
> functions to build a fully qualified domain name from the id.

No, it's not a tree structure.
The question is why not serialize it?
I vote for not serializing it because when I get the data from the database, 
I don't have to join the 2 tables (the domain name is on both tables).

CREATE TABLE domain (name    CHAR(30) PRIMARY KEY
);

CREATE TABLE nodes (id    SERIAL,name    CHAR(30),domain    CHAR(30) REFERENCES domain ("name")
);

This is a better approach then putting a SERIAL value to the domain table and 
making nodes.domain reference to that SERIAL? Why?

Saludos... :-)

-- 
Porqué usar una base de datos relacional cualquiera,
si podés usar PostgreSQL?
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Martín Marqués                  |        mmarques@unl.edu.ar
Programador, Administrador, DBA |       Centro de Telematica                      Universidad Nacional
        del Litoral
 
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