FireDAC读取数据Delphi

procedure TForm1.btnReadDataClick(Sender: TObject);
var
sql : String;

myConn : TFDConnection;
myQry : TFDQuery;
mySource : TDataSource;

myCursor : TFDGUIxWaitCursor ;

begin

// myCursor := TFDGUIxWaitCursor.Create(nil);

sql := 'Select * From tpUsers';

myConn := TFDConnection.Create(nil);
myConn.ConnectionDefName := 'TestMySQL';
myConn.LoginPrompt := false;
myConn.Open();

myQry := TFDQuery.Create(nil);
myQry.Connection := myConn;
myQry.SQL.Clear();
myQry.SQL.Text := sql;
myQry.Open();

mySource := TDataSource.Create(nil);
mySource.DataSet := myQry;
Self.dbgrd2.DataSource := mySource;

end;