primary_key
- 1.0.0
- 1.1.6
- 1.2.6
- 2.0.3
- 2.1.0
- 2.2.1
- 2.3.8
- 3.0.0
- 3.0.9
- 3.1.0
- 3.2.1
- 3.2.8
- 3.2.13
- 4.0.2
- 4.1.8
- 4.2.1
- 4.2.7
- 4.2.9
- 5.0.0.1 (0)
- 5.1.7 (38)
- 5.2.3 (0)
- 6.0.0 (2)
- 6.1.3.1 (0)
- 6.1.7.7 (0)
- 7.0.0 (0)
- 7.1.3.2 (0)
- 7.1.3.4 (0)
- What's this?
primary_key(name, type = :primary_key, **options)
public
Defines the primary key field. Use of the native PostgreSQL UUID type is supported, and can be used by defining your tables as such:
create_table :stuffs, id: :uuid do |t| t.string :content t.timestamps end
By default, this will use the gen_random_uuid() function from the pgcrypto extension. As that extension is only available in PostgreSQL 9.4+, for earlier versions an explicit default can be set to use uuid_generate_v4() from the uuid-ossp extension instead:
create_table :stuffs, id: false do |t| t.primary_key :id, :uuid, default: "uuid_generate_v4()" t.uuid :foo_id t.timestamps end
To enable the appropriate extension, which is a requirement, use the enable_extension method in your migrations.
To use a UUID primary key without any of the extensions, set the :default option to nil:
create_table :stuffs, id: false do |t| t.primary_key :id, :uuid, default: nil t.uuid :foo_id t.timestamps end
You may also pass a custom stored procedure that returns a UUID or use a different UUID generation function from another library.
Note that setting the UUID primary key default value to nil will require you to assure that you always provide a UUID value before saving a record (as primary keys cannot be nil). This might be done via the SecureRandom.uuid method and a before_save callback, for instance.