Title: Reset Paradox Auto-incremental field
Question: How can I easily reset an auto-incremental field in a Paradox table?
Answer:
If theres anyone who still use Paradox files, this is a good tip:
Sometimes, we have to erase all records of a table that has auto-increment fields. When you try to append some new records to this table, the auto-incremental field does not reset itself. So how can we reset this number ?
The solution: this simple function expects the Paradox table filename and the new counter and returns if the operation is sucessfull.
function ResetAutoInc(FileName: TFileName; NewValue:Longint): Boolean;
begin
with TFileStream.Create(FileName, fmOpenReadWrite) do
try
Result := (Seek($49, soFromBeginning) = $49) and (Write(NewValue, 4) = 4);
finally
Free;
end;
end;
I tested this function with Paradox 7 files.
If someone has older formats please test it and put a note on this article.
Thanks to my colleague Isnard who gave me this valueable tip.
Health and Freedom,
Josir.