Question

I am attempting to create a function that incorporates multiple ‘With’ Statements.

My original Query is:

WITH EmpCount as 
  (
    SELECT job.EmployeeID, assign.PropertyID FROM EmployeeJobstatus job 
    JOIN Assignment assign ON job.JobID = assign.ID  GROUP by job.EmployeeID,
    assign.PropertyID
  ),
    NoDup as 
  (
    SELECT EmployeeID, Count(employeeID) as NO from EmpCount 
    Group by EmployeeID HAVING count(Employeeid) > 1
  )

    SELECT prop.Name, job.EmployeeID, Emp.EmpID, Emp.Name 
    from EmployeeJobStatus job
    JOIN Assignment assign ON assign.id = job.jobid
    JOIN Property prop ON prop.ID = assign.PropertyID
    JOIN Employee emp on emp.ID = job.EmployeeID
    WHERE EmployeeID IN (SELECT EmployeeID from NoDup)
    GROUP By prop.Name, EmployeeID, emp.EmpID,Emp.Name
    Order BY EmployeeID

This returns:

Name           EmployeeID   EmpID         Name
Property 1      23         1286333      LastNameRemoved1, Rachel A
Property 2      23         1286333      LastNameRemoved1, Rachel A
Property 2      76         1268329      LastNameRemoved2, Tamer A
Property 1      76         1268329      LastNameRemoved2, Tamer A
Property 3      135        1411933      LastNameRemoved3, Sarah E
Property 1      135        1411933      LastNameRemoved2, Sarah E

My function needs to return a ‘Y’ or a ‘N’ depending on whether or not they were cross property, utilizing the fields in EmployeeJobStatus StartDate and EndDate.

I have only started my function, as I have no idea what to do next.

CREATE function dbo.IsEmployeeCrossPropertyOnDate
 (@EmpID int, @AsOfDate datetime) 
  RETURNS INT AS

Any help, or a nudge in the right direction would be much appreciated. Thank you.

Answer 1

How about this…

CREATE FUNCTION dbo.IsEmployeeCrossPropertyOnDate
    (
        @empid int
        , @asofdate datetime
    )
RETURNS TABLE
AS
RETURN
    SELECT
        CASE MIN(a.propertyid)
            WHEN MAX(a.propertyid)
                THEN 'N'
            ELSE 'Y'
        END CrossProp
    FROM 
        EmployeeJobStatus j
    JOIN 
        Assignment a
        ON a.id = j.jobid
    WHERE 
        j.employee = @empid
        AND j.startdate <= @AsOfDate
        AND j.endDate > @AsOfDate
    GROUP BY 
        j.employeeid;

EDIT:

You’d probably outer apply it, rather than cross. Nulls would then be employees with no assignments at the point in time.

EDIT 2:

Since you asked, below is a scalar function. Just be careful of scalars. Depending on where you use it in a query, the BEGIN END block can fool the optimizer into going RBAR.

CREATE FUNCTION dbo.IsEmployeeCrossPropertyOnDate
    (
        @empid int
        , @asofdate datetime
    )
RETURNS CHAR(1)
AS
BEGIN
    DECLARE @res CHAR(1) = 'N';

    SELECT @res = 
        CASE MIN(a.propertyid)
            WHEN MAX(a.propertyid)
                THEN 'N'
            ELSE 'Y'
        END 
    FROM 
        EmployeeJobStatus j
    JOIN 
        Assignment a
        ON a.id = j.jobid
    WHERE 
        j.employee = @empid
        AND j.startdate <= @AsOfDate
        AND j.endDate > @AsOfDate
    GROUP BY 
        j.employeeid;

    RETURN @res;
END;