Hi!
If use a query, for example,

do
$$
DECLARE v_BegDat TimeStamp;
begin
  v_BegDat := :BegDat;
  perform v_BegDat as result;
end;
$$;

then the parameter (BegDat) is determined and i can configure it. But when the query is executed, a "[FireDAC][Phys][libpq] ОШИБКА: ошибка синтаксиса (примерное положение ":")." error occurs. Most likely the parameter value is not substituted into the final query.