create or alter procedure test_cursor
returns (
    res_text varchar(255))
as
begin
  for select rdb$description, rdb$relation_id, rdb$security_class, rdb$character_set_name, rdb$linger
  from rdb$database
  as cursor cur_db do
  begin
    res_text = cur_db.rdb$character_set_name;
  end
  suspend;
end

create or alter procedure test_cursor
returns (
    res_text varchar(255))
as
declare variable "CUR_DB.RDB$CHARACTER_SET_NAME";
begin
  for select rdb$description, rdb$relation_id, rdb$security_class, rdb$character_set_name, rdb$linger
  from rdb$database
  as cursor cur_db do
  begin
    res_text = cur_db.rdb$character_set_name;
  end
  suspend;
end