java.util.UUID.randomUUID().toString();

and set directly either as a field variable on instantiation or sometimes in an interceptor on save.

On a recent project we had to migrate some data across some new entities and needed something outside the application to generate the UUID values for each record. I knew that PostgreSQL supported UUID generation – though I had never used this before – and even has a UUID data type. Getting to the function itself proved a little more challenging as it isn’t actually included on a typical installation and is found within the postgres-contrib package. So, to install…

apt-get install postgresql-contrib
sudo su -c "psql pdrivers < /usr/share/postgresql/8.4/contrib/uuid-ossp.sql" postgres

The above installs the relevant contrib package, and creates the UUID functions from the script within the unpacked contrib directory (substitute version as required). We are also installing the function as a superuser (postgres in this case) as we need a user with the ability to install functions using C code.

To generate UUID values execute as follows:

SELECT uuid_generate_v1();

c1b84d24-90c9-11e0-aa50-33cd7e76d901
e9e3b374-90c9-11e0-8f0f-df46bcf47f20
eea6fba0-90c9-11e0-9ce0-a33175edde97

Some good references on the available functions can be found here with some further info on the package OSSP UUID pages here.

Check out version 3.1.0 here http://executequery.org
Feedback most welcome. Contributions most welcome.

I do plan for future releases to be more incremental and frequent.