Uniqueidentifier data type for postgresql.
Copyright (C) 2001-2003, Dmitry G. Mastrukov <[email protected]>
Portion Copyright (C) 1996, 1997 Theodore Ts'o
Portion Copyright (C) 2002 Hussein Patni
Portion Copyright (C) 2003 David Bradford

This software is distributed under the GNU Lesser General Public License
either version 2, or (at your option) any later version.


This data type is a 16-byte uniqueidentifier widely used to unique identify 
entities across Universe. This implementation depends on libuuid from 
e2fsprogs package (http://e2fsprogs.sourceforge.net) by Theodore Ts'o. I don't
know is it possible to build e2fsprogs not on Linux, but seems libuuid itself 
is fairly portable. So it may be possible to cut libuuid from e2fsprogs and
compile it alone. Seems Theodore has some plans to split linuuid from 
e2fsprogs.

You should place this package in "contrib" directory of postgresql. To build
and install package you need to enter

    make
    make install (may be as superuser)
    
Next you should go to share/contrib directory of your postgresql installation
and enter

    psql your_database -f uniqueidentifier.sql
    
Type will be registered in your database (if you install new type in temlate1
database it will be available in every newly created database).

Now you can use uniqueidentifier data type in column definitions and indexes.

This package provides function newid(). This function generates new
uniqueidentifier and may be used in DEFAULT constraints or in functions.

Example:

CREATE TABLE test (
    id uniqueidentifier PRIMARY KEY DEFAULT newid()
};

INSERT INTO TABLE test VALUES (newid());    

Hussein Patni <[email protected]> contibuted function 
text(uniqueidentifier) to convert uniqueidentifier to text datatype.
There exists implicit cast from uniqueidentifier to text.

Example:

SELECT CAST(id AS text) from test;
SELECT text(id) from test;
SELECT 'test/' || id from test;

David Bradford <[email protected]> contibuted function 
newid(uniqueidentifier) to create uniqueidentifier from text.
There exists implicit cast from text to uniqueidentifier.

Updated for use with PostgreSQL 9.1 and extensions by Auto Data Direct, Inc.

Enjoy!

Dmitry G. Mastrukov
[email protected]