Filtered DistinctCount Measure and MDX Not Delivering Same Results as SQL - sql

Question

I have the following two queries, one SQL, one MDX:
SQL:
SELECT t.term_report_year, COUNT(*)
FROM(
SELECT DISTINCT de.term_report_year, fe.student_id
FROM warehouse.FactEnrolments fe
INNER JOIN warehouse.DimDate dd
ON fe.term_record_creation_fk = dd.DateKey
INNER JOIN warehouse.DimTermEnrolments de
ON fe.term_enrolments_fk = de.term_enrolments_pk
WHERE dd.ISOWeekNumberOfYear <= 8 OR dd.ISOYearCode < de.term_report_year
) t
GROUP BY t.term_report_year
ORDER BY term_report_year
MDX:
SELECT
NON EMPTY
Measures.[Enrolments] ON COLUMNS
,NON EMPTY
Filter
(
[Term Enrolments].[Term Year].Children *
[Term Record Creation].[ISO Year Code].children *
[Term Record Creation].[ISO Week Number Of Year].children
,
Cint([Term Record Creation].[ISO Week Number Of Year].CurrentMember.Member_Key) <= 8
OR
Cint([Term Record Creation].[ISO Year Code].CurrentMember.Member_key) < Cint([Term Enrolments].[Term Year].CurrentMember.Member_key)
) ON ROWS
FROM [Enrolments];
I am trying to express the idea in both, "count the number of students in a year who enrolled for that year before or during the 8th week of that year" where year = term_year.
In my SSAS cube the Enrolments measure is a DistinctCount on student_id. In the SQL query, term_report_year is equivalent to Term Year in the MDX.
Could someone please explain why the two queries are not delivering the same numbers e.g. the SQL for 2016 gives 2803 and the MDX 2948?
I think it has something to do with the MDX double counting across the weeks, but I can't work out how to fix it.

Answer 1

Try this. I am hopeful it will filter the year total to just weeks <= 8
SELECT
NON EMPTY
Measures.[Enrolments] ON COLUMNS
,NON EMPTY [Term Enrolments].[Term Year].Children ON ROWS
FROM (
SELECT
Filter
(
[Term Enrolments].[Term Year].Children *
[Term Record Creation].[ISO Year Code].children *
[Term Record Creation].[ISO Week Number Of Year].children
,
Cint([Term Record Creation].[ISO Week Number Of Year].CurrentMember.Member_Key) <= 8
OR
Cint([Term Record Creation].[ISO Year Code].CurrentMember.Member_key) < Cint([Term Enrolments].[Term Year].CurrentMember.Member_key)
) ON COLUMNS
FROM [Enrolments]
);