[Postgres] Using uuid-ossp extenstion

PostgreSQL allows you store and compare UUID values but it does not include functions for generating the UUID values in its core.

Instead, it relies on the third-party modules that provide specific algorithms to generate UUIDs. For example the uuid-ossp module provides some handy functions that implement standard algorithms for generating UUIDs.

To install the uuid-ossp module, you use the CREATE EXTENSION statement as follows:

CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

 

To generate the UUID values based on the combination of computer’s MAC address, current timestamp, and a random value, you use the uuid_generate_v1() function:

SELECT uuid_generate_v1();

 

Update a data:

update Users set user_handle = uuid_generate_v4() where last_name = 'clark';