--
-- workflow_case__get_task_id/2
--
create or replace function workflow_case__get_task_id(
  integer,
  integer
) returns int4 as $$

declare
  get_task_id__case_id         alias for $1;
  get_task_id__transition_key  alias for $2;
  v_task_id                    integer;
begin

  select task_id into v_task_id
  from wf_tasks
  where case_id = get_task_id__case_id and
    transition_key = get_task_id__transition_key;

  if not found then
    raise error 'Case % has no transition with key %', get_task_id__case_id, get_task_id__transition_key;

  return v_task_id;

end;$$ language plpgsql;