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Helper III
Helper III

M Code Recursive function dynamic column reference

I would like to try dynamic expanding columns in M code.


The code is:

fxFactorial = (RowCount as number, Tnumber as number, tbl as table) =>
displayname = "disPath" & Text.From(Tnumber),
childrenname = "children" & Text.From(Tnumber),
prevchildname = "children" & Text.From(Tnumber-1) ,
prevstep = tbl ,
Source2 = Table.ExpandListColumn( prevstep, prevchildname),
#"Added disPath2" = Table.AddColumn(Source2, displayname, each Record.Field(prevchildname,"displayPath") ),
#"Added children2" = Table.AddColumn(#"Added disPath2", childrenname, each try Record.Field([children1],"children") otherwise null ),
ColRowCount = List.NonNullCount( #"Added children2"[children2]),
titlenumber = Tnumber + 1,
subresult = if titlenumber > 2 then @fxFactorial(ColRowCount, titlenumber, #"Added children2") else #"Added children2"
#"Added disPath2"


But, I'm getting an error stating like We cannot convert the value "children1" to Record



Much appreciated it if someone showed some light on this query.


You are using the prevchildname variable (a text value) in a function that expects a record (Record.Field).



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