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Re: Serial field

From: A_Schnabel(at)t-online(dot)de (Andre Schnabel)
To: <pgsql-novice(at)postgresql(dot)org>
Subject: Re: Serial field
Date: 2001-07-13 05:45:26
Message-ID: 002d01c10b5f$04b5b360$ (view raw, whole thread or download thread mbox)
Lists: pgsql-novice

does anybody know, what happens, if a client-app. generates it's own id

(SELECT max(id)+1 from org),

Will the next insert of just a name throw an error? (duplicate value on
primary key?)
I never tried that. But I do have a postgresql server accessed by two
clients. An old one (generating it's own id's) an a newer one (using DEFAULT
values). So I wrote my own function with pl/pgsql to generate my id's.
If I could handle the duplicate values with a sequenc, maybe it would be the
easier way.

kind regards,
----- Original Message -----
From: Jason Earl
To: webmaster(at)robbyslaughter(dot)com ; Francois Thomas ;
Sent: Friday, July 13, 2001 3:39 AM
Subject: RE: [NOVICE] Serial field
....Once you know how the
serial type actually works it becomes straightforward
to simply create the table like:

processdata=> CREATE TABLE orgs (id int primary key,
name char(10));
NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit
index 'orgs_pkey' for table 'orgs'

Once the table is created you can easily import your
data in whatever manner makes you the happiest.  Once
your data is imported it is a simple manner to find
out the largest value for (or whatever) with a
select statement like this:

SELECT max(id) FROM orgs;

Then create a new sequence with a start value one
higher than the value that is returned:

CREATE SEQUENCE orgs_id_seq START <value>;

Once you have got a sequence then you simply alter the
table so that it gets it's default values from that

alter table orgs alter id set default

Presto, you have just created an auto increment field
from the ground up.

Hope this is helpful,

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Subject: TR: Serial field
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