let update_query = fun q ~name ~query ~comment ->
if q.qry_name <> name then begin
validate_name_exn name;
begin
match query_by_name_opt q.qry_db name with
| None -> q.qry_name <- name
| Some _ -> raise (Duplicated_name name)
end;
end;
q.qry_query <- query;
q.qry_comment <- comment