Don't understand creation statement's answer

Hi,

In the long term I'm willing to construct a Little Java application that
runs a library. I was looking to create a few table & connect them
according to a non existing model . To create the Author table here's
what I thought doing for a table that should only contain The Name & the
Surname of the Author (once per Author).

<snip>
tsmets=> create sequence author_seq;
CREATE

tsmets=> create table author (
tsmets=> author_id numeric primary key default
nextval('author_seq'),
tsmets=> name char(25) not null,
tsmets=> surname char(25) not null
tsmets=> );
NOTICE: CREATE TABLE/PRIMARY KEY will create implicit index
'author_pkey' for table 'author'
CREATE
tsmets=> \d author
Table "author"
Attribute | Type | Modifier
-----------+---------------+----------------------------------------------
author_id | numeric(30,6) | not null default
nextval('author_seq'::text)
name | char(25) | not null
surname | char(25) | not null
Index: author_pkey

tsmets=>
</snip>

Now the question is :
What is the meaning of the following statement in the table description
?

Attribute | Type | Modifier
-----------+---------------+----------------------------------------------
author_id | numeric(30,6) | not null default
nextval('author_seq'::text)

Why was my author_id changesdin a "nextval('author_seq'::text)".
There's no text here ?

That for highlighting the meaning of this ?

Thomas,

--
Sun Dec 17 19:42:31 CET 2000

Thomas SMETS e-mail : tsmets(at)altern(dot)org
Av. de la Brabançonne 133 / 3 Tel. : +32 (0)2 742. 05. 94.
1030 Bruxelles
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