split or merge values in a table based on data in date field

Id	sid	Startdate	enddate	    Reasonid classid Acyearid schoolid
1	1	5/1/2013	8/1/2013	1	1	1	1
2	1	10/1/2013	12/1/2013	2	1	1	1
3	2	12/12/2012	20/12/2012	1	1	1	1
4	2	5/1/2013	7/1/2013	3	1	1	1

Id	sid	Startdate	enddate    Reasonid classid Acyearid schoolid
1	1	3/1/2013	6/1/2013	2	1	1	1

Id	sid	Startdate	enddate	  Reasonid  classid Acyearid	schoolid
2	1	10/1/2013	12/1/2013	2	1	1	1
3	2	12/12/2012	20/12/2012	1	1	1	1
4	2	5/1/2013	7/1/2013	3	1	1	1
5	1	3/1/2013	6/1/2013	2	1	1	1
6	1	7/1/2013	8/1/2013	1	1	1	1

Id	sid	Startdate	enddate    Reasonid classid Acyearid	schoolid
1	1	5/1/2013	12/1/2013	2	1	1	1

Id	sid	Startdate	enddate	  Reasonid classid  Acyearid	schoolid
3	2	12/12/2012	20/12/2012	1	1	1	1
4	2	5/1/2013	7/1/2013	3	1	1	1
5	1	5/1/2013	12/1/2013	2	1	1	1

Id	sid	Startdate	enddate	  Reasonid  classid Acyearid	schoolid
1	1	6/1/2013	9/1/2013	2	1	1	1

Id	sid	Startdate	enddate	  Reasonid  classid Acyearid	schoolid
2	1	10/1/2013	12/1/2013	2	1	1	1
3	2	12/12/2012	20/12/2012	1	1	1	1
4	2	5/1/2013	7/1/2013	3	1	1	1
5	1	3/1/2013	5/1/2013	1	1	1	1
6	1	5/1/2013	9/1/2013	2	1	1	1

declare @StartDate smalldatetime='2013-02-12 00:00:00';   
declare @EndDate smalldatetime='2013-02-15 00:00:00';  
declare @Notes nvarchar(500);    
declare @AbsentReasonCode int; 
   --12 - 19 => 12 - 15,16 - 19 
declare @_StartDateTable smalldatetime ;   
declare   @_EndDateTable smalldatetime ; 
declare @_AbsentReasonCode int  ;
declare @_update int=0; 
declare CursorAttendance cursor for 
select StartDate,EndDate,AbsentReasonCode from attendance 
where StartDate<@EndDate and EndDate>@StartDate and StudentID=@StudentID
order by StartDate;
--case 1
open CursorAttendance;
FETCH NEXT
FROM CursorAttendance INTO @_StartDateTable , @_EndDateTable,@_AbsentReasonCode 
	WHILE @@FETCH_STATUS = 0
	BEGIN
	set @_update=0;
	while dbo.GetDatePart(@_StartDateTable)<dbo.getdatepart(@_enddatetable)>=dbo.GetDatePart(@StartDate)
		and dbo.GetDatePart(@_StartDateTable)<= dbo.GetDatePart(@EndDate)
		begin 
			set @_update=1;
			
		end
	--else if dbo.GetDatePart(@_StartDateTable)<dbo.getdatepart(@startdate)>dbo.GetDatePart(@EndDate)
			begin
			print('****--------splited date for student 42457,AttendanceID=100 -----*****');
			set @_update=0;
			print (cast( @StartDate as nvarchar(50))+','+cast(@EndDate as nvarchar(50)));
			print (cast( @_StartDateTable as nvarchar(50))+','+cast(@_EndDateTable as nvarchar(50)));
			print('****--------------*****');
			--print(@_StartDateTable)print(@_EndDateTable);
			--insert into dbo.Attendance values( @StartDate,@EndDate);
			--insert into dbo.Attendance values( @_StartDateTable,@_EndDateTable,@_AbsentReasonCode);
			--delete from Attendance where AttendanceID=@AttendanceID;
			--
			end
			else if @_update=2
			begin
			print('****------@_update=2-------*****');
			end
			
		end		
	-------------------------------------------
	
	
	FETCH NEXT
	FROM CursorAttendance INTO @_StartDateTable , @_EndDateTable,@_AbsentReasonCode 	END
CLOSE CursorAttendance
DEALLOCATE CursorAttendance
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