Blob in DB Speichern

[peschai]

Hallo
Schematisch in etwa so

"DataSet" symbolisiert deine Tabelle ...

1.) Daten in Stream zwischenlagern
2.) Zum schreiben öffnen mit "Edit"
3.) Stream in Blobfield schreiben
4.) Schreiben abschliessen mit "Post"

Delphi-Quellcode:

function  MyObject.FieldWriteAsBlob(const FieldName:String;Const aStream:TStream):Boolean;
var
  j1:TField;
begin
  Result := False;
  j1 := Nil;
  Try
    if Assigned(DataSet) then
      begin
        j1 := DataSet.FieldByName(FieldName);
        If assigned(j1) then
          begin    
            if j1.IsBlob then
               begin
                 DataSet.Edit;
                 if Assigned(aStream)
                   then TBlobField(j1).LoadFromStream(aStream)
                   else TBlobField(j1).Clear;
                 DataSet.Post;
                 Result := True;
               end;
          end; 
        end;
    except
      on e:exception do
        begin
          Result := False;
          DataSet.Cancel;
          //.... Exception melden ?
        end;
    end;
end;

procedure MyObject.btnPictureWriteClick(Sender: TObject);
var
  ms1:TMemoryStream;
  s2:STring;
  i9:integer;  
begin
  // local init
  ms1  := Nil;
  s2   := '';
  i9 := 0;
  { Action }
  try
    try
      if Assigned(DataSet) then
        begin
          if Not(DataSet.ReadOnly) then
            begin
              DataSet.Activate;
              ms1 := TMemoryStream.Create;
              if OpenPictureDialog1.Execute then
                begin
                  ms1.LoadFromFile(OpenPictureDialog1.FileName);
                  ms1.Seek(0, soFromBeginning);
                  MyObject.FieldWriteAsBlob('BlobFeldName',ms1);
                  ms1.Clear;
                end;
            end;
        end;
    except
      on E:Exception do
        begin
          s2 := e.Message;
          // ....
        end;
    end;
  finally
    FreeAndNil(ms1);
  end;
end;