Create new table applying cartesian logic

[jeronimo2334]

Hello all, I have 3 tables, 2 of them are dimensional:

DIM TABLE - EXAMS

exam1

exam2

exam3

DIM TABLE - STUDENTS

student1

student2

student3

FACT TABLE - RESULTS

exam2	student1	fail
exam2	student1	pass
exam3	student1	pass
exam1	student2	fail
exam2	student2	pass
exam2	student3	pass
exam3	student3	pass

I am trying to get a new table combining all these tables, it needs a row for each exam and each student and whether they pass, failed or not taken then exam.
Note, student1 failed exam2 on the 1st row, but then passed it on the 2nd row. The expected table should only show the passed result.

EXPECTED TABLE

exam1	student1	not taken
exam2	student1	pass
exam3	student1	pass
exam1	student2	fail
exam2	student2	pass
exam3	student2	not taken
exam1	student3	not taken
exam2	student3	pass
exam3	student3	pass

Any help is appreciated.
Thanks.

[AlB]

Hi @jeronimo2334 

Place the following M code in a blank query to see the steps for your expected table. 

See it all at work in the attached file.

let
    Source = ExamsT,
    #"Added Custom" = Table.AddColumn(Source, "Custom", each StudentsT),
    #"Expanded Custom" = Table.ExpandTableColumn(#"Added Custom", "Custom", {"Student"}, {"Student"}),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded Custom",{{"Student", type text}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"Exam", "Student"}, ResultsT, {"Exam", "Student"}, "ResultsT", JoinKind.LeftOuter),
    #"Expanded ResultsT" = Table.ExpandTableColumn(#"Merged Queries", "ResultsT", {"Result"}, {"Result"}),
    #"Replaced Value" = Table.ReplaceValue(#"Expanded ResultsT",null,"Not taken",Replacer.ReplaceValue,{"Result"})
in
    #"Replaced Value"

Please accept the solution when done and consider giving a thumbs up if posts are helpful.  Contact me privately for support with any larger-scale BI needs, tutoring, etc.

[jeronimo2334]

Thank you! That is almost the expected result. I edited my post, adding a small gotcha.
Issue being, a student can have multiple entries in the Results table, with a fail and a pass grade. The expected table should show only the pass if there is a case of multiple results. It should only show the fail result if there is no pass result.

[CNENFRNL]

Simple enough

[AlB]

@jeronimo2334

Can the results only be pass or fail?

Please accept the solution when done and consider giving a thumbs up if posts are helpful.  Contact me privately for support with any larger-scale BI needs, tutoring, etc.

[jeronimo2334]

Correct.

[AlB · Accepted solution]

@jeronimo2334  Updated to meet that additional requirement

Place the following M code in a blank query to see the steps for your expected table. 

See it all at work in the attached file.

let
    Source = ExamsT,
    #"Added Custom" = Table.AddColumn(Source, "Custom", each StudentsT),
    #"Expanded Custom" = Table.ExpandTableColumn(#"Added Custom", "Custom", {"Student"}, {"Student"}),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded Custom",{{"Student", type text}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"Exam", "Student"}, ResultsT, {"Exam", "Student"}, "ResultsT", JoinKind.LeftOuter),
    #"Expanded ResultsT" = Table.ExpandTableColumn(#"Merged Queries", "ResultsT", {"Result"}, {"Result"}),
    #"Replaced Value" = Table.ReplaceValue(#"Expanded ResultsT",null,"Not taken",Replacer.ReplaceValue,{"Result"}),
    #"Sorted Rows" = Table.Buffer(Table.Sort(#"Replaced Value",{{"Exam", Order.Ascending}, {"Student", Order.Ascending}, {"Result", Order.Descending}})),
    #"Removed Duplicates" = Table.Distinct(#"Sorted Rows", {"Exam", "Student"})
in
    #"Removed Duplicates"

Please accept the solution when done and consider giving a thumbs up if posts are helpful.  Contact me privately for support with any larger-scale BI needs, tutoring, etc.

[jeronimo2334]

Thank you that worked. The pbix seems to be from some other post but the M query is right.

[AlB]

@jeronimo2334 

Corrected the pbix