Here is how I setup my SQL Script to pull the data into an XML File.

SELECT(select s.StudentNumber As DisplayID, s.PersonID AS ExternalAccountID, sc.number AS SchoolID,s.FirstName, s.LastName, s.Gender,

CONVERT(varchar,s.birthdate,101) AS Birthdate, s.Grade AS GradeLevel,

CASE WHEN ts.PhysicalDate IS NOT NULL THEN CONVERT(varchar,ts.physicaldate,101)ELSE '' END As LastPhysicalDate,

MAX(CASE WHEN pe.eligibility ='F' THEN '3'WHEN pe.eligibility = 'R' THEN '2'ELSE '1'END) As EconomicIndicator

FROM student s

JOIN SchoolYear sy ON sy.endYear = s.endYear

LEFT JOIN TempScreening ts ON ts.personid = s.personID

JOIN calendar ca ON ca.calendarID = s.calendarID

JOIN School sc ON sc.schoolID = ca.schoolid

LEFT JOIN POSEligibility pe on pe.personid = s.personid

where studentnumber IS NOT NULL and sy.active = 1 and s.endDate IS NULL or s.endDate >=GETDATE()

AND ca.schoolID NOT IN( 12,13,32,16,34,14,15,25)

GROUP BY s.studentNumber, s.personID, sc.number,s.firstName, s.lastName,s.gender, s.birthdate, s.grade,ts.physicaldate

FOR XML PATH('Student'), root('Students')

)as Data

Hope this helps