Delphi

Str := 'UPDATE tblTransaction SET tblTransaction.Category = "' + NewCat+ '", ' +
            'tblTransaction.TaxDeductable="' + NewExp + '" ' +
            'WHERE (((tblTransaction.Category) = "ZZZZ"));';
  cmdCategory.CommandText := Str;
  cmdCategory.Execute;
  ShowData;

//and then this bit in the ShowData procedure

  with qryCategory do
  begin
    Active := False;        //I also tried Close and Open
    ConnectionString := cnnStr;
    SQL.Text := 'SELECT Category,Expense FROM tblCategory ORDER BY Category';
    Active := True;
  end;

//The DBGrid should now show this change

ADODataSet1.Close;
ADODataSet1.CommandText:='SELECT Category,Expense FROM tblCategory ORDER BY Category';
ADODataSet1.Open;

with dsCategory do  //now a DataSet
  begin
    Close;
    ConnectionString := cnnStr;  //cnnStr comes from Form1.
    CommandText := 'SELECT Category,Expense FROM tblCategory ORDER BY Category';
    Open;
  end;