How to copy TDataSet record with ftMemo fields?
lazarus / 16-Databases

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vladvons · 2013-10-20 12:26

I want to save and paste all fields in DataSet record, so i use 'array
of variant' as backup storage.

No problem reading DataSet fields into an array, but after writing
values back from array into a DataSet all fields with ftMemo type
remains empty.

Code: [Select]procedure TDmRefItem.CloneRecord(aDataSet: TDataSet);
var
  i: Integer;
  ArrBackUp: array of Variant;
begin
  SetLength(ArrBackUp, aDataSet.FieldCount);
  for i := 0 to aDataSet.FieldCount - 1 do
     ArrBackUp[i] := aDataSet.Fields[i].Value 

  aDataSet.Append();

  for i := 0 to aDataSet.FieldCount - 1 do
  begin
    if (aDataSet.Fields[i].DataType = ftMemo) then
      aDataSet.Fields[i].Value :=  ArrBackUp[i]
      //aDataSet.Fields[i].AsString :=  ArrBackUp[i];
      //aDataSet.Fields[i].Text :=  ArrBackUp[i];
    else
      aDataSet.Fields[i].Value :=  ArrBackUp[i]
  end;
end;

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vladvons · 2013-10-21 12:19

Even simle assignment string variable to memo field does nothing.
Lets assume that aDataSet.FieldByName('Descr').DataType is ftMemo,
then following code doest work properly
Code: [Select]aDataSet.FieldByName('Descr').Value := 'My string';
String1 := aDataSet.FieldByName('Descr').Value;
// String1 is 'Null' now

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LacaK · 2013-10-21 12:39

Can you please post here same simple application, which will show
error ? (f.e. using TBufDataSet)