Обсуждение: Primary Key
Hi I try to do the following in a table that has 4 columns, id - month - day- time The column id is the primary key, for example id - month . day - time 1 Jan 22 16:15 2 Jan 22 16:16 3 Jan 22 16:17 4 Jan 22 16:18 But I pretend that automatically when I made an INSERT INTO table (month, day, time) values (A,B,C) the primary key update his value increasing by one I dont know how to do this, Iam using Postgres 7.4 with PgAdminIII Thank you
If you want to use a primary key that increase in value by one each time consider using a sequence. See http://www.postgresql.org/docs/7.4/static/sql-createsequence.html On Mon, Jun 14, 2004 at 07:17:37PM -0500, Eduardo V. Rodríguez wrote: > Hi > > I try to do the following in a table that has 4 columns, > > id - month - day- time > > The column id is the primary key, for example > > id - month . day - time > 1 Jan 22 16:15 > 2 Jan 22 16:16 > 3 Jan 22 16:17 > 4 Jan 22 16:18 > > But I pretend that automatically when I made an INSERT INTO table (month, > day, time) values (A,B,C) the primary key update his value increasing by one > > > I dont know how to do this, Iam using Postgres 7.4 with PgAdminIII > > Thank you > > ---------------------------(end of broadcast)--------------------------- > TIP 8: explain analyze is your friend
Eduardo V. Rodríguez wrote: > id - month . day - time > 1 Jan 22 16:15 > 2 Jan 22 16:16 > 3 Jan 22 16:17 > 4 Jan 22 16:18 > > But I pretend that automatically when I made an INSERT INTO table (month, > day, time) values (A,B,C) the primary key update his value increasing by one CREATE TABLE foo (id_foo SERIAL PRIMARY KEY, month ...); SERIAL is of type int creates automatically a sequence that increments each time you don't specify the id in an INSERT. HTH -- e-Trolley Sayegh & John, Nabil Sayegh Tel.: 0700 etrolley /// 0700 38765539 Fax.: +49 69 8299381-8 PGP : http://www.e-trolley.de
On Mon, Jun 14, 2004 at 19:17:37 -0500, "Eduardo V. Rodríguez" <evazquez@insys-corp.com.mx> wrote: > > But I pretend that automatically when I made an INSERT INTO table (month, > day, time) values (A,B,C) the primary key update his value increasing by one > > > I dont know how to do this, Iam using Postgres 7.4 with PgAdminIII Depending on what you really want sequences might be the solution. Sequences really only provide you with unique values. If you really need the values not have any gaps in the numbers then you will need to do more work (especially if you will be deleting rows).
Ok thanks for all the ideas I got it -----Original Message----- From: Bruno Wolff III [mailto:bruno@wolff.to] Sent: Wednesday, June 16, 2004 1:13 PM To: Eduardo V. Rodríguez Cc: Postgres (E-mail) Subject: Re: [NOVICE] Primary Key On Mon, Jun 14, 2004 at 19:17:37 -0500, "Eduardo V. Rodríguez" <evazquez@insys-corp.com.mx> wrote: > > But I pretend that automatically when I made an INSERT INTO table (month, > day, time) values (A,B,C) the primary key update his value increasing by one > > > I dont know how to do this, Iam using Postgres 7.4 with PgAdminIII Depending on what you really want sequences might be the solution. Sequences really only provide you with unique values. If you really need the values not have any gaps in the numbers then you will need to do more work (especially if you will be deleting rows).