enum.md

Add new enum values

Postgres 9.1 and above:

-- ALTER TYPE name ADD VALUE new_enum_value [ { BEFORE | AFTER } existing_enum_value ]

ALTER TYPE enum_type ADD VALUE 'new_value'; -- appends to list
ALTER TYPE enum_type ADD VALUE 'new_value' BEFORE 'old_value';
ALTER TYPE enum_type ADD VALUE 'new_value' AFTER 'old_value';

Display enum list in Postgres:

select enum_range(null::<your_enum>);

Example usage

CREATE TYPE action_type AS ENUM ('commented_by', 'answered_by', 'reacted_by');
select enum_range(null::action_type);

CREATE TYPE subscription_type AS ENUM ('question', 'answer', 'comment');
select enum_range(null::subscription_type);
ALTER TYPE subscription_type ADD VALUE 'reaction' AFTER 'answer';