pg.ddx.io pgsql-sql@postgresql.org mailing list archive
help / color / mirror / Atom feedHow to autoincrement a primary key...
5+ messages / 5 participants
[nested] [flat]
* How to autoincrement a primary key...
@ 2006-09-22 19:13 Doug Hyde <doug.hyde@e-cocreate.com>
0 siblings, 1 reply; 5+ messages in thread
From: Doug Hyde @ 2006-09-22 19:13 UTC (permalink / raw)
To: pgsql-sql
I am sure this is simple, but I don't get it. I am new to PGSQL, coming from
MySQL - in mysql, you can autoincrement the primary key; in postgre, I am
not sure how to do this. I have read the documentation, and tried "nextval"
as the default - I have searched for the datatype SERIAL, but I am using
navicat and this datatype is not supported. Can someone tell me how to do
this - I just want the integer value for a primary key to autoincrement by
one.
Thanks,
Doug
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: How to autoincrement a primary key...
@ 2006-09-22 19:25 Richard Broersma Jr <rabroersma@yahoo.com>
parent: Doug Hyde <doug.hyde@e-cocreate.com>
0 siblings, 2 replies; 5+ messages in thread
From: Richard Broersma Jr @ 2006-09-22 19:25 UTC (permalink / raw)
To: Doug Hyde <doug.hyde@e-cocreate.com>; pgsql-sql
> I am sure this is simple, but I don't get it. I am new to PGSQL, coming from
> MySQL - in mysql, you can autoincrement the primary key; in postgre, I am
> not sure how to do this. I have read the documentation, and tried "nextval"
> as the default - I have searched for the datatype SERIAL, but I am using
> navicat and this datatype is not supported. Can someone tell me how to do
> this - I just want the integer value for a primary key to autoincrement by
> one.
CREATE TABLE bar (id SERIAL PRIMARY KEY);
Is just shorthand notation for:
CREATE SEQUENCE foo START 1;
CREATE TABLE bar (id integer PRIMARY KEY DEFAULT nextval('bar'));
Also see:
http://www.postgresql.org/docs/8.1/interactive/sql-createtable.html
http://www.postgresql.org/docs/8.1/interactive/sql-createsequence.html
Regards,
Richard Broersma Jr.
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: How to autoincrement a primary key...
@ 2006-09-22 22:00 Andrew Chilton <andychilton@gmail.com>
parent: Richard Broersma Jr <rabroersma@yahoo.com>
1 sibling, 0 replies; 5+ messages in thread
From: Andrew Chilton @ 2006-09-22 22:00 UTC (permalink / raw)
To: pgsql-sql
On 23/09/06, Richard Broersma Jr <rabroersma@yahoo.com> wrote:
> Is just shorthand notation for:
>
> CREATE SEQUENCE foo START 1;
> CREATE TABLE bar (id integer PRIMARY KEY DEFAULT nextval('bar'));
Doug, just a slight typo correction in that second line Richard gave
you (bar should be foo), it should read in full:
CREATE SEQUENCE foo START 1;
CREATE TABLE bar (id integer PRIMARY KEY DEFAULT nextval('foo'));
Andy
--
name: Andrew Chilton
web: http://kapiti.geek.nz/
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: How to autoincrement a primary key...
@ 2006-09-22 22:12 Thomas Kellerer <spam_eater@gmx.net>
parent: Richard Broersma Jr <rabroersma@yahoo.com>
1 sibling, 1 reply; 5+ messages in thread
From: Thomas Kellerer @ 2006-09-22 22:12 UTC (permalink / raw)
To: pgsql-sql
Richard Broersma Jr wrote on 22.09.2006 21:25:
>> I am sure this is simple, but I don't get it. I am new to PGSQL, coming from
>> MySQL - in mysql, you can autoincrement the primary key; in postgre, I am
>> not sure how to do this. I have read the documentation, and tried "nextval"
>> as the default - I have searched for the datatype SERIAL, but I am using
>> navicat and this datatype is not supported. Can someone tell me how to do
>> this - I just want the integer value for a primary key to autoincrement by
>> one.
>
> CREATE TABLE bar (id SERIAL PRIMARY KEY);
>
>
> Is just shorthand notation for:
>
> CREATE SEQUENCE foo START 1;
> CREATE TABLE bar (id integer PRIMARY KEY DEFAULT nextval('bar'));
>
Well the shorthand notation has a minor gotcha: you cannot drop the sequence
that has been created automatically. Only if you drop the column itself. Should
not be a problem, but it is a difference between a SERIAL PRIMARY KEY definition
and the "verbose" mode
Thomas
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: How to autoincrement a primary key...
@ 2006-09-23 06:27 Aarni Ruuhimäki <aarni@kymi.com>
parent: Thomas Kellerer <spam_eater@gmx.net>
0 siblings, 0 replies; 5+ messages in thread
From: Aarni Ruuhimäki @ 2006-09-23 06:27 UTC (permalink / raw)
To: pgsql-sql; +Cc: Doug Hyde <doug.hyde@e-cocreate.com>
On Saturday 23 September 2006 01:12, Thomas Kellerer wrote:
> Richard Broersma Jr wrote on 22.09.2006 21:25:
> >> I am sure this is simple, but I don't get it. I am new to PGSQL, coming
> >> from MySQL - in mysql, you can autoincrement the primary key; in
> >> postgre, I am not sure how to do this. I have read the documentation,
> >> and tried "nextval" as the default - I have searched for the datatype
> >> SERIAL, but I am using navicat and this datatype is not supported. Can
> >> someone tell me how to do this - I just want the integer value for a
> >> primary key to autoincrement by one.
> >
> > CREATE TABLE bar (id SERIAL PRIMARY KEY);
> >
> >
> > Is just shorthand notation for:
> >
> > CREATE SEQUENCE foo START 1;
> > CREATE TABLE bar (id integer PRIMARY KEY DEFAULT nextval('foo'));
>
> Well the shorthand notation has a minor gotcha: you cannot drop the
> sequence that has been created automatically. Only if you drop the column
> itself. Should not be a problem, but it is a difference between a SERIAL
> PRIMARY KEY definition and the "verbose" mode
>
> Thomas
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match
Verbosily you can have even more control over the sequence.
With SERIAL the default is something like
CREATE SEQUENCE foo
INCREMENT BY 1
NO MAXVALUE
NO MINVALUE
CACHE 1;
By hand you can define e.g.
CREATE SEQUENCE foo
START n
INCREMENT BY n
MAXVALUE n
MINVALUE n
CACHE 1;
BR,
Aarni
--
Aarni Ruuhimäki
**Kmail**
**Fedora Core Linux**
^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2006-09-23 06:27 UTC | newest]
Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2006-09-22 19:13 How to autoincrement a primary key... Doug Hyde <doug.hyde@e-cocreate.com>
2006-09-22 19:25 ` Richard Broersma Jr <rabroersma@yahoo.com>
2006-09-22 22:00 ` Andrew Chilton <andychilton@gmail.com>
2006-09-22 22:12 ` Thomas Kellerer <spam_eater@gmx.net>
2006-09-23 06:27 ` Aarni Ruuhimäki <aarni@kymi.com>
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox