>Ann,
>
>>> On Jul 22, 2014, at 9:47 AM, "'checkmail' check_mail@... [firebird-
>>> support]" <firebird-support@yahoogroups.com> wrote:
>>> I would like to read every n record, depending on number of records.
>>
>> Do you care if your results are repeatable? If so, you'll have to sort all the
>> records then skip records in the result set.
>
>I don't think that the answer matters.
>
>Given that FB doesn't have the notion of ROW_Number within a result set, I don't see how the OP can filter to only see every nth row.

I thought this question was answered long ago (with MOD)... What about something like:

execute block returning(<resulting fields>) AS
declare variable i integer;
begin
i = 0;
for select <whatever> into <resulting fields> do
begin
i = i + 1;
if (i = 2) then suspend;
if (i = 5) then i = 0;
end
end

I think this will return record 2, 7, 12 etc.(of course there would have to be an ORDER BY for the result to be repeatable.

Set