Use cross apply function - sql-server

Question

I have this cross apply query and I want to sum the result of it
CROSS APPLY
(SELECT
SUM(CASE WHEN [day] BETWEEN #FirstDay AND #LastDay
THEN 1 ELSE 0
END) AS UsedDays
FROM
Calendar c
WHERE
([day] >= r.[DateFrom]
AND [day] <= r.[DateTo]
AND [WorkDay] = 1)) calculateUsedDays
I have a request table that contains different requests from different people
and my point is to sum all of the days from the requests from a person.
The cross apply returns the sum of the days by every request from the requests table for every person.
For example:
person
John, usedDays - 5
John, - 7
Peter - 10
Peter - 5
..
And I want to sum these days and group by name of the person so that I can have all of the days by person.
Example:
John - 12
Peter - 15
I tried with sum and group by , but it returns error:
Each GROUP BY expression must contain at least one column that is not an outer reference
Thank you :))

Answer 1

Thank you guys,
I solved this, but now my problem is: Implicit conversion from data type datetime to int is not allowed. Use the CONVERT function to run this query.
This is my code
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [core].[ReportBalanceYearSearch]
#Year int = NULL,
#TypeOfLeaveGid int = NULL,
#IsActive int = NULL
AS
BEGIN
SET NOCOUNT ON
DECLARE #Err int
DECLARE #sql nvarchar (max), #paramlist nvarchar(max)
DECLARE #FirstDay datetime
DECLARE #LastDay datetime
DECLARE #typeLeaveGid INT, #typeCreditGid INT, #relLeaveToCreditGid INT
SET #FirstDay = DATEFROMPARTS ( #Year, 1, 1)
SET #LastDay = DATEFROMPARTS ( #Year, 12, 31)
SELECT #typeLeaveGid = gid FROM Nomenclature WHERE type = 'RequestType' and Code = 1
SELECT #typeCreditGid = gid FROM Nomenclature WHERE type = 'RequestType' and Code = 2
SELECT #relLeaveToCreditGid = gid FROM Nomenclature WHERE type = 'Relation' and Code = 6
SELECT #sql = '
SELECT u.[Name],
u.[DepartmentGid],
sum(calculateUsedDays.UsedDays - isnull(calculateCreditDays.CreditDaysInPeriod,0)) as [UsedDays],
ub.[Balance],
sum(calculateUsedDays.UsedDays - isnull(calculateCreditDays.CreditDaysInPeriod,0)) + ub.[Balance] as [TotalDaysInYear],
r.[LeaveTypeGid]
FROM [dbo].[Request] r
inner join [User] u on r.[UserGid] = u.[Gid]
inner join [UserBalance] ub on r.[UserGid] = ub.UserGid and ub.Year = #xYear
LEFT OUTER JOIN dbo.Request CRD
inner join Relations rel ON rel.RelID2 = CRD.Gid AND rel.RelType = #xrelLeaveToCreditGid
inner join Nomenclature nsc ON nsc.Gid = CRD.StatusGid
cross apply (SELECT
sum(case when [day] between COALESCE(#xFirstDay, [day]) AND COALESCE(#xLastDay, [day]) then 1 else 0 end) as CreditDaysInPeriod
FROM Calendar c
WHERE [day] >= crd.[DateFrom] AND [day] <= crd.[DateTo] AND [WorkDay] = 1 ) calculateCreditDays
ON rel.RelID1 = r.Gid
and CRD.TypeGid = #xtypeCreditGid
cross apply (SELECT
sum(case when [day] between #xFirstDay and #xLastDay then 1 else 0 end) as UsedDays
FROM Calendar c
WHERE ([day] >= r.[DateFrom] AND [day] <= r.[DateTo] AND [WorkDay] = 1))calculateUsedDays
where #xYear = DATEPART(year,r.[DateFrom]) and r.TypeGid = #xtypeLeaveGid and #xIsActive IS NULL OR u.[Active] = #xIsActive
group by u.[Name], u.[DepartmentGid],r.[LeaveTypeGid], ub.[Balance]'
SELECT #paramlist ='
#xTypeOfLeaveGid int,
#xFirstDay datetime,
#xYear int,
#xLastDay datetime,
#xtypeLeaveGid int,
#xrelLeaveToCreditGid int,
#xtypeCreditGid int,
#xIsActive bit'
EXEC sys.sp_executesql #sql, #paramlist,
#TypeOfLeaveGid,
#Year,
#IsActive,
#typeLeaveGid,
#relLeaveToCreditGid,
#typeCreditGid,
#FirstDay,
#LastDay
SET #Err = ##Error
RETURN #Err
END