How to store a query containing more than 15000 characters in a variable of nvarchar(max)

Question

I have the following string and I want to store it in variable using SQL Server 2008 R2 . I can't store this string using variable of nvarchar(max) .
' SELECT    A.[EmployeeCode] ,A.[EmployeeId] ,A.[Name],A.[DepartmentCode],A.[DesignationCode]   
, A.[CompanyCode]  ,A.[Department] ,A.[Designation] ,A.[Entity]
, A.[GovtAdministrativeAreaCode]   ,A.[WorkingUnitCode],A.[WorkingUnitName]
, isnull(L.WorkingDays ,0) as  TotalWorkingDays ,isnull(K.DelayHr,0) as DelayHr
, isnull(J.OTHr,0) as OTHr ,isnull(B.[4Hr],0) as [4Hr]
, isnull(C.[10Hr],0) as [10Hr] ,isnull(D.[12Hr],0) as [12Hr]
, isnull(E.NoOfPresent,0) as NoOfPresent   , isnull(F.NoOfAbsent,0 )as NoOfAbsent
, isnull(G.NoOfLeave ,0) as NoOfLeave , isnull(H.Morning ,0) as Morning
, isnull(I.Night,0) as Night , isnull(L.[NoOfW/HDay] ,0) as [NoOfW/HDay]
, isnull(K.NoOfDelay,0) as NoOfDelay , isnull(L.TotalDayAttends,0) as TotalDayAttends
, isnull(M.[LessThan4Hr] ,0) as [LessThan4Hr]
, isnull (N.NoOfNoOutTime,0) as NoOfNoOutTime
INTO '
+@tableName+'
FROM
( SELECT DISTINCT [EmployeeCode] ,[EmployeeId] ,[Name],[DepartmentCode],[DesignationCode]
  ,[CompanyCode]  ,[Department] ,[Designation] ,[Entity]
  ,[GovtAdministrativeAreaCode]   ,[WorkingUnitCode],[WorkingUnitName]
  FROM [vwHR_DailyAttendanceSummary]
  WHERE AttendanceDate between  dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
) A
LEFT JOIN
(   SELECT [EmployeeCode]     ,WorkingUnitCode      ,Count([AttendanceDate] ) as [4Hr]
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]  
  FROM [vwHR_DailyAttendanceSummary]
  WHERE AttendanceDate between   dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
  and (DATEDIFF(MINUTE,InTime,OutTime))/60 >=4 and (DATEDIFF(MINUTE,InTime,OutTime))/60 <10
  group by EmployeeCode ,WorkingUnitCode   ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]  
) B ON (B.EmployeeCode=A.EmployeeCode and B.WorkingUnitCode=A.WorkingUnitCode
and B.DepartmentCode=A.DepartmentCode and B.DesignationCode=A.DesignationCode and B.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
(       SELECT [EmployeeCode]      ,WorkingUnitCode       ,Count([AttendanceDate] ) as [10Hr]
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]     
FROM [vwHR_DailyAttendanceSummary]
WHERE AttendanceDate between    dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''') 
and (DATEDIFF(MINUTE,InTime,OutTime))/60 >=10 and (DATEDIFF(MINUTE,InTime,OutTime))/60 <12
group by EmployeeCode,WorkingUnitCode  ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]   
)C ON (C.EmployeeCode=A.EmployeeCode and C.WorkingUnitCode=A.WorkingUnitCode
and C.DepartmentCode=A.DepartmentCode and C.DesignationCode=A.DesignationCode and C.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
(   SELECT [EmployeeCode]     ,WorkingUnitCode   ,Count([AttendanceDate] ) as [12Hr]
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]     
  FROM [vwHR_DailyAttendanceSummary]
  WHERE AttendanceDate between  dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
  and (DATEDIFF(MINUTE,InTime,OutTime))/60 >=12
  group by EmployeeCode,WorkingUnitCode    ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) D on (D.EmployeeCode=A.EmployeeCode and D.WorkingUnitCode=A.WorkingUnitCode
and D.DepartmentCode=A.DepartmentCode and D.DesignationCode=A.DesignationCode and D.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
(   SELECT [EmployeeCode]  ,WorkingUnitCode   ,COUNT(Status) NoOfPresent
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
  FROM [vwHR_DailyAttendanceSummary]
  WHERE Status = ''P'' and AttendanceDate between   dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''') 
  group by EmployeeCode,WorkingUnitCode,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
  ) E on (E.EmployeeCode =A.EmployeeCode and E.WorkingUnitCode=A.WorkingUnitCode
and E.DepartmentCode=A.DepartmentCode and E.DesignationCode=A.DesignationCode and E.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
  (   SELECT [EmployeeCode],WorkingUnitCode  ,COUNT(Status) NoOfAbsent
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
  FROM [vwHR_DailyAttendanceSummary]
  WHERE Status = ''A'' and AttendanceDate between  dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
  group by EmployeeCode,WorkingUnitCode  ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) F on (F.EmployeeCode=A.EmployeeCode and F.WorkingUnitCode = A.WorkingUnitCode
and F.DepartmentCode=A.DepartmentCode and F.DesignationCode=A.DesignationCode and F.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
       ( SELECT  la.CompanyCode , la.EmployeeCode ,lad.LeaveDate ,A.WorkingUnitCode,A.DepartmentCode,A.DesignationCode,W.AdminAreaCode
FROM [vwLMS_EmployeeLeaveInformation] la
inner JOIN LMS_LeaveApplicationDetail  lad on (lad.LeaveApplicationCode=la.LeaveApplicationCode and lad.ActionType <> ''DELETE'')
inner join HR_DailyAttendanceSummary A on (A.EmployeeCode=la.EmployeeCode and A.AttendanceDate=lad.LeaveDate and A.ActionType <> ''DELETE'')
inner join General_WorkingUnit W on (w.WorkingUnitCode=A.WorkingUnitCode and W.ActionType <> ''DELETE'')
WHERE  la.ApplicationStatus=1 and  la.JobStatus in (1,0)
and lad.LeaveDate between   dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')  
) G  on ( G.EmployeeCode=A.EmployeeCode and G.WorkingUnitCode=A.WorkingUnitCode
and G.DepartmentCode= A.DepartmentCode and G.DesignationCode= A.DesignationCode and G.AdminAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
(   SELECT [EmployeeCode] ,WorkingUnitCode ,Count([AttendanceDate] ) as [Morning] 
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]        
  FROM [vwHR_DailyAttendanceSummary]
  WHERE AttendanceDate between  dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
  and (DATEDIFF(MINUTE,InTime,OutTime))/60 >=8 and DATEPART(HH,InTime)=6 and DATEPART(HH,OutTime)>=14
  group by EmployeeCode,WorkingUnitCode    ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) H On (H.EmployeeCode=A.EmployeeCode and H.WorkingUnitCode=A.WorkingUnitCode
and H.DepartmentCode=A.DepartmentCode and H.DesignationCode=A.DesignationCode and H.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT Join
(   SELECT [EmployeeCode]   ,WorkingUnitCode       ,Count([AttendanceDate] ) as [Night]
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]          
  FROM [vwHR_DailyAttendanceSummary]
  WHERE AttendanceDate between    dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
  and (DATEDIFF(MINUTE,OutTime,InTime))/60 >=8
  and DATEPART(HH,InTime)>=19
  and DATEPART(HH,OutTime)>=5
  group by EmployeeCode ,WorkingUnitCode ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) I on (I.EmployeeCode=A.EmployeeCode and I.WorkingUnitCode=A.WorkingUnitCode
and I.DepartmentCode=A.DepartmentCode and I.DesignationCode=A.DesignationCode and I.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
( SELECT distinCt [EmployeeCode]
,sum(TotalOverTime ) as OTHr
,WorkingUnitCode
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
FROM vwHR_DayBasisOvertime  
WHERE AttendanceDate between   dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
group by EmployeeCode ,WorkingUnitCode ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) J ON (J.EmployeeCode=A.EmployeeCode and J.WorkingUnitCode=A.WorkingUnitCode
and J.DepartmentCode=A.DepartmentCode and J.DesignationCode=A.DesignationCode and J.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)  
LEFT JOIN  
(   SELECT distinCt A.[EmployeeCode]  
,DelayHr=CASE
WHEN sum(DATEDIFF(mi,A.AttendanceDate + A.ShifIn, A.InTime)) >0 THEN SUM( DATEDIFF(mi,A.AttendanceDate +A.ShifIn, A.InTime))
WHEN sum(DATEDIFF(mi,A.AttendanceDate +A.ShifIn, A.InTime))<0 THEN 0
END
,Count(A.AttendanceDate) as NoOfDelay
, WorkingUnitCode
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
  FROM [vwHR_DailyAttendanceSummary] A
  WHERE A.Status=''D'' AND AttendanceDate between   dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''') 
  group by A.EmployeeCode ,WorkingUnitCode,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) K On (K.EmployeeCode=A.EmployeeCode and K.WorkingUnitCode=A.WorkingUnitCode
and K.DepartmentCode=A.DepartmentCode and K.DesignationCode=A.DesignationCode and K.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
INNER JOIN
( select  EmployeeCode ,WorkingUnitCode 
/*, [A/L Time],[No Of A/L Day],[Total Working Day Time] */
, [No Of working Day] as WorkingDays
, ([No Of W Day]+[No Of H Day]) as [NoOfW/HDay]
,[Total At] as TotalDayAttends
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
from '
+@OutPutTableName_WorkingDaysHours+'
) L ON (L.EmployeeCode=A.EmployeeCode and l.WorkingUnitCode=A.WorkingUnitCode
and L.DepartmentCode=A.DepartmentCode and L.DesignationCode=A.DesignationCode and L.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)
LEFT JOIN
(   SELECT [EmployeeCode]  ,WorkingUnitCode ,Count([AttendanceDate] ) as [LessThan4Hr] 
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]   
  FROM [vwHR_DailyAttendanceSummary]
  WHERE AttendanceDate between   dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''')
  and (DATEDIFF(MINUTE,InTime,OutTime))/60 >0 and (DATEDIFF(MINUTE,InTime,OutTime))/60 <4
  group by EmployeeCode,CompanyCode ,WorkingUnitCode    ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) M ON (M.EmployeeCode=A.EmployeeCode and M.WorkingUnitCode=A.WorkingUnitCode
and M.DepartmentCode=A.DepartmentCode and M.DesignationCode=A.DesignationCode and M.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode )
left join
( SELECT EmployeeCode  ,WorkingUnitCode , COUNT(AttendanceDate) as NoOfNoOutTime
,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode]  
FROM vwHR_DailyAttendanceSummary
WHERE  AttendanceDate between dbo.fxn_cDate('''
+@DateFrom+''')
and dbo.fxn_cDate('''+@DateTo+''') 
and OutTime is null
group by EmployeeCode ,WorkingUnitCode ,[DepartmentCode] ,[DesignationCode]    ,[GovtAdministrativeAreaCode] 
) N ON (N.EmployeeCode=A.EmployeeCode and N.WorkingUnitCode=A.WorkingUnitCode
and N.DepartmentCode=A.DepartmentCode and N.DesignationCode=A.DesignationCode and N.GovtAdministrativeAreaCode=A.GovtAdministrativeAreaCode)

Answer 1

If you are concatenating multiple strings together to make a nvarchar(max), and the result is too long to store in the largest possible regular regular nvarchar (that is nvarchar(4000), you must be sure the concatenation is done as nvarchar(max).  If
you don't, each of the concatenations is done according to the type of each operand.  And, if the two things being concatenated are both (for example) nvarchar(20), then the result is nvarchar(40) because 20+20 is 40.  But if the two things being
concatenated are both nvarchar(3000), the result does not become nvarchar(max), it is nvarchar(4000) - because 3000 + 3000 is 6000, but that's two big, so you get 4000.  For a simple example
Declare @Result nvarchar(max), @Input1 nvarchar(3000), @Input2 nvarchar(3000);
Set @Input1 = Replicate('a', 3000);
Set @Input2 = Replicate('b', 3000);
Set @Result = @Input1 + @Input2;
Select 'Test1', Len(@Result), Len(@Input1), Len(@Input2);
Set @Result = Cast(@Input1 As nvarchar(max)) + @Input2;
Select 'Test2', Len(@Result), Len(@Input1), Len(@Input2);
In Test1, the two 3000 character nvarchars are concatenated together, but the result is truncated to nvarchar(4000).  That is then put in an nvarchar(max), but the result is already truncated to 4000 characters, so in Test1 the length of @Result is
4000.  In Test2, the first operand is converted to nvarchar(max), so the concatenation result is nvarchar(max) and you get the length you expect in @Result (that is, 6000).
So the solution to your problem is to force the first item in your concatenation to be of type nvarchar(max).  Then the result of the concatenation of the first and second will be nvarchar(max), then SQL concatenates the third term and gets nvarchar(max),
etc.  So the final result contains the whole string you want.  So you want to do
CAST(' SELECT A.[EmployeeCode] ,A.[EmployeeId] ,A.[Name],A.[DepartmentCode],A.[DesignationCode]
, A.[CompanyCode] ,A.[Department] ,A.[Designation] ,A.[Entity]
, A.[GovtAdministrativeAreaCode] ,A.[WorkingUnitCode],A.[WorkingUnitName]
, isnull(L.WorkingDays ,0) as TotalWorkingDays ,isnull(K.DelayHr,0) as DelayHr
, isnull(J.OTHr,0) as OTHr ,isnull(B.[4Hr],0) as [4Hr]
, isnull(C.[10Hr],0) as [10Hr] ,isnull(D.[12Hr],0) as [12Hr]
, isnull(E.NoOfPresent,0) as NoOfPresent , isnull(F.NoOfAbsent,0 )as NoOfAbsent
, isnull(G.NoOfLeave ,0) as NoOfLeave , isnull(H.Morning ,0) as Morning
, isnull(I.Night,0) as Night , isnull(L.[NoOfW/HDay] ,0) as [NoOfW/HDay]
, isnull(K.NoOfDelay,0) as NoOfDelay , isnull(L.TotalDayAttends,0) as TotalDayAttends
, isnull(M.[LessThan4Hr] ,0) as [LessThan4Hr]
, isnull (N.NoOfNoOutTime,0) as NoOfNoOutTime
INTO ' AS nvarchar(max))
+@tableName+'
--- Etc for the rest of your expression
Tom