#112 in memory table with memo fields

[Carlo]

Hello
I have a memory table containing some memo fields. (table.Storage := stoMemory).
It gives me a "divide by zero" error when I try to add a record.
If I set table.Storage := stoFile, everything works fine.

The error is raised in
unit dbf_memo;
procedure TMemoFile.WriteMemo(var BlockNo: Integer; ReadSize: Integer; Src: TStream);
because RecordSize=0, the test
if ((bytesBefore + Src.Size + bytesAfter + RecordSize-1) div RecordSize) <= ((ReadSize + RecordSize-1) div RecordSize) then........ raise the error.

I've modified the code in this way:

** if RecordSize = 0 then
boolVar := ((bytesBefore + Src.Size + bytesAfter + RecordSize - 1)) <= ((ReadSize + RecordSize - 1))
else
boolVar := ((bytesBefore + Src.Size + bytesAfter + RecordSize - 1) div RecordSize) <= ((ReadSize + RecordSize - 1) div RecordSize);
if boolVar then..........**

and in my case it works.

I'm submitting this correction, in case you would like to use it to correct the code.

Kind regards.

[Paul Baker]

Can you provide a short program that reproduces this? I see the concern with the code, but if RecordSize is 0, there is a bigger issue.

[Carlo]

Hello
This is the code that raises the error when I post the new record:

~~~
constructor TmyClass.create;
begin
FTable := TDbf.create(nil);
FTable.TableName := 'Table.dbf';
FTable.Storage := stoMemory;
With FTable do
begin
Close;
TableLevel := 7;
Exclusive := True;
with FieldDefs do
begin
clear;
add('tag', ftString, 80, False);
add('FIELD1', ftMemo, 0, False);
add('FIELD2', ftMemo, 0, False);
end;
CreateTable;
Open;
AddIndex('idxByTag', 'tag', [ixPrimary, ixUnique]);
end;
FTable.append;
FTable.FieldByName('TAG').AsString := 'xx';
FTable.FieldByName('FIELD1').AsString := 'yyyyyyyyyyyy yyyyyyyyyyyyyyyyy yyyyyyyyyyyyyyyy';
FTable.FieldByName('FIELD2').AsString := 'zzzzzzzzzz zzzzzzzzzzzzzzzzz zzzzzzzzz';
FTable.Post;
end;
~~~**

The modification that I've described in my previus post doesn't work!

thank you for your reply

[Paul Baker]

I can reproduce it using this code.

Unfortunately, it looks like when you open a table, it can only open the associated memo if it actually exists as a file. I don't think you'll be able to solve it with a minor change like you suggested.

We would have to add a feature, and I don't know who has time to do it.

Maybe there is a different way you can achieve what you need?

[Carlo]

I agree with you about the impossibility of solving the problem with small changes.
The change I made avoids division by zero but after this operation nothing works anymore.
Anyway, thanks for your help