TBlobStream

Here are some examples of how to use the TBlobStream to get text from a memofield.

{This one copies from one memo field to another.}

procedure TForm1.Button1Click(Sender: TObject);
var
b1, b2: TBlobStream;
begin
b1 := TBlobStream.create(Table1Notes, bmRead);
try
    table2.edit;
    b2 := TBlobStream.create(Table2MyBlob, bmReadWrite);
    try
      b2.CopyFrom(b1, b1.size);
    finally
      b2.free;
    end;
finally
    b1.free;
end;
table2.post;
end;

{Write to a stream.}
procedure TForm1.Button1Click(Sender: TObject);
var
Stream: TBlobStream;
s: string;
begin
table1.edit;
Stream := TBlobStream.Create(Table1Notes, bmReadWrite);
try
    Stream.Seek(0, 2); {Seek 0 bytes from the stream's end point (2).}
    s := 'Lloyd is really cool.';
    Stream.write(s[1], length(s));
finally
    Stream.Free;
end;
table1.post;
end;

{Read from a stream.}
procedure TForm1.Button1Click(Sender: TObject);
var
Buffer: PChar;
Size: Integer;
Stream: TBlobStream;
begin
{ Here is how it is done from a query: }
{ Stream := TBlobStream.Create(query1.FieldByName('MemoField') as TBlobField, bmRead);}

Stream := TBlobStream.Create(Table1MemoField, bmRead);
try
    Size := Stream.Seek(0, 2);
    Stream.Seek(0, 0);
    Inc(Size);
    GetMem(Buffer, Size);
    try
      FillChar(Buffer^, Size, #0);
      Stream.Read(Buffer^, Size);
      Memo1.SetTextBuf(Buffer);
    finally
      FreeMem(Buffer, Size);
    end;
finally
    Stream.Free;
end;
end;