Postgres: plpgsql drop enum value function

drop_enum_value.sql

-- two functions to add and remove values from an enum.
-- reason: there's no easy way of removing a value from an existing enum in postgres.

CREATE OR REPLACE FUNCTION utility.enum_add_value(nspname text, typname text, value text) RETURNS void
AS $$
  BEGIN
    INSERT INTO pg_enum (enumtypid, enumlabel, enumsortorder)
    VALUES (
             (
               SELECT oid
               FROM pg_type
               WHERE pg_type.typname = enum_add_value.typname
                 AND pg_type.typnamespace = (SELECT oid FROM pg_namespace WHERE pg_namespace.nspname = enum_add_value.nspname)
             ),
             enum_add_value.value,
             ( SELECT MAX(enumsortorder) + 1 FROM pg_enum WHERE enumtypid IN (
               SELECT oid
               FROM pg_type
               WHERE pg_type.typname = enum_add_value.typname
                 AND pg_type.typnamespace = (SELECT oid FROM pg_namespace WHERE pg_namespace.nspname = enum_add_value.nspname)
             ) )
           );
  END;
$$
LANGUAGE plpgsql;

COMMENT ON FUNCTION utility.enum_add_value (text, text, text) IS E'@omit';

-----------------------------------------

CREATE OR REPLACE FUNCTION utility.enum_drop_value(nspname text, typname text, value text) RETURNS void
AS $$
BEGIN
  DELETE FROM pg_enum
  WHERE enumlabel = value
    AND enumtypid = (
    SELECT oid
    FROM pg_type
    WHERE pg_type.typname = enum_drop_value.typname
      AND pg_type.typnamespace = (
        SELECT oid FROM pg_namespace WHERE pg_namespace.nspname = enum_drop_value.nspname
      )
    );
END;
$$
  LANGUAGE plpgsql;

Assumes there are namespaces in place. Definitely high risk to use, but a lot easier then updating all functions/columns/triggers relying on an enum type already.