LKBEN11378: Howto auto increment a field in postgres sql

Symptom

You need to create a serial to auto increment an ID in a database table

Cause

This can be used as a primary key if you need one

Solution

PostgreSQL supports a SERIAL data type. This will automatically create a sequence. e.g.:

    CREATE TABLE persons (
        id   SERIAL,
    sirname TEXT,
        name TEXT
    );

This will be translated into the following:

    CREATE SEQUENCE persons_id_seq;
    CREATE TABLE persons (
        id   INT4 NOT NULL DEFAULT nextval(person_id_seq),
    sirname TEXT,
        name TEXT
    );

Automatically created sequences are named <tablename>_<serialcolumn>_seq. For more information take a look at the create_sequence manual page.

Disclaimer:

The information provided in this document is intended for your information only. Lubby makes no claims to the validity of this information. Use of this information is at own risk!

About the Author

Author: Wim Peeters - Keskon GmbH & Co. KG

Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience, including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform.