TFieldGetData (Delphi)

Description

This example requires a button, a test edit, and a populated ClientDataSet. Pipe the ClientDataSet through a DataSource to a DGGrid or DBNavigator to control the current field. Cast the data correctly according to the field type when assigning to the test edit.

Code

{$IFNDEF UNICODE}
uses SwSystem;
{$ENDIF}
 
procedure TForm1.Button1Click(Sender: TObject);
var MyBuffer: Pointer;
begin
{ Retrieve the "raw" data from Field1. }
with CDS.Fields[0] do
  begin
    if not IsBlob then { This does not work for BLOB fields. }
    begin
      { Allocate space. }
      MyBuffer:= GetMemory(DataSize);
      try
        if not GetData(MyBuffer) then
          MessageDlg(DisplayName + ' is NULL', mtInformation, [mbOK], 0)
        else
          { Do something with the data. };
          Edit1.Text:= string(PAnsiChar(MyBuffer)); // For a stringfield
      finally
        { Free the space. }
        FreeMem(MyBuffer, DataSize);
      end;
    end;
  end;
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
{$IFDEF UNICODE}
  CDS.LoadFromFile(GetCurrentDir + '\CDS.XML');
{$ELSE}
  CDS.LoadFromFile(gsAppPath + 'CDS.XML');
{$ENDIF}
end;

Uses

• Data.DB.TBCDField ( fr | de | ja )
• Data.DB.TBooleanField ( fr | de | ja )
• Data.DB.TBytesField ( fr | de | ja )
• Data.DB.TDateField ( fr | de | ja )
• Data.DB.TDateTimeField ( fr | de | ja )
• Data.DB.TField.DataSize ( fr | de | ja )
• Data.DB.TFloatField ( fr | de | ja )
• Data.DB.TFMTBCDField ( fr | de | ja )
• Data.DB.TIntegerField ( fr | de | ja )
• Data.DB.TLargeintField ( fr | de | ja )
• Data.DB.TSmallintField ( fr | de | ja )
• Data.DB.TSQLTimeStampField ( fr | de | ja )
• Data.DB.TStringField ( fr | de | ja )
• Data.DB.TTimeField ( fr | de | ja )
• Data.DB.TVarBytesField ( fr | de | ja )
• Data.DB.TWordField ( fr | de | ja )
• Data.DB.TField.GetData ( fr | de | ja )
• Data.DB.TBlobField.IsBlob ( fr | de | ja )
• Data.DB.TField.DisplayName ( fr | de | ja )
• System.GetMemory ( fr | de | ja )