Thanks for the replies,
I have one question regarding this comment...
"You also need to add a DEFAULT expression and optionallymake the sequence
owned by the column:"
What difference does it make if a table "owns" a sequence of not?...does this
contraint the use of the sequence to ONLY that one table?
The sequence will only be used to auto-increment the id column in order to have
an automatic primary key. Could I then somehow use the sequence for all tables
which need this?
yours,
Rob
________________________________
Von: Boszormenyi Zoltan <z...@cybertec.at>
An: pgsql-general@postgresql.org
Gesendet: 13:43 Dienstag, 4.Oktober 2011
Betreff: Re: [GENERAL] auto-increment column
2011-10-04 13:30 keltezéssel, Robert Buckley írta:
Hi,
>
>
>I have a column in a table called hist_id with the datatype "integer". When I
>created the table I assigned this column the primary key constraint but didn´t
>make it an auto-increment column.
>
>
>How could I do this to an the already existing column?
>
>
>I have created the sequence with the following command but don´t know how to
>change the existing column to auto-increment.
>
>
>
>
>$ create sequence hist_id_seq;
You also need to add a DEFAULT expression and optionally
make the sequence owned by the column:
ALTER TABLE tablename ALTER COLUMN hist_id SET DEFAULT
nextval('hist_id_seq');
ALTER SEQUENCE hist_id_seq OWNED BY tablename.hist_id;
The "ALTER SEQUENCE ... OWNED BY ..." will make the sequence
automatically dropped if this column or table is dropped.
>
>thanks for any help,
>
>
>Rob
--
----------------------------------
Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de http://www.postgresql.at/
