Regarding Execute Query() GroupBy Field

Hi,

I am having a form which contains a Datasource name of Table3,  it has 3 fields ( Days, LastDoneDate, NextScheduleDate )

the Table Contains the following Record

LastDoneDate     NextScheduleDate        Day

1/1/2012               1/6/2013                        20.00

1/1/2011               1/5/2013                        10.00

1/1/2011               1/5/2013                        10.00

in the Form i have to show the Record as GroupBy the Three fields.

same way i have written the coding in Datasource ExecuteQuery

public void executeQuery()

{

   this.query().dataSourceName('Table3').clearRanges();

   this.query().dataSourceName('Table3').addGroupByField(fieldnum(Table3, Days));

   this.query().dataSourceName('Table3').addGroupByField(fieldnum(Table3, LastDoneDate));

   this.query().dataSourceName('Table3').addGroupByField(fieldnum(Table3, NextScheduleDate));

   super();

}

It;s showing me the perfect Output in the Form Grid as GroupBy, it showing 2 records as data as available in Table..

But the Problem is when im Sorting the Form Grid The Records are not Showing as GroupBy . Its showing the Entire 3 records.

Please tel me where i have done Mistake