How do I set a default value for a UUID primary key column in Postgres?
In order to use uuid_generate_v4()
, you first need to execute:
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
If the column id
already exists in the table and you want to modify it by making it the primary key and adding a default value, you can do it in 2 steps:
ALTER TABLE my_object_times ADD PRIMARY KEY (id);
ALTER TABLE my_object_times ALTER COLUMN id SET DEFAULT uuid_generate_v4();
If the column doesn't exist at all, then you can create it with all the attributes you want, by simply doing:
ALTER TABLE my_object_times ADD id uuid PRIMARY KEY DEFAULT uuid_generate_v4();
(I cannot test this right now but it should work)