Modifing data based on a correction table

Hi DanFromMontreal ,

Please try the following code:

let

    #"Unpivot tblData" = Table.UnpivotOtherColumns(tblData, {"RowID"}, "Attribute", "Value"),
    #"Unpivot tblCorrection" = Table.UnpivotOtherColumns(tblCorrection, {"RowID"}, "Attribute", "Value"),
    Source = Table.NestedJoin(#"Unpivot tblData", {"RowID", "Attribute"}, #"Unpivot tblCorrection", {"RowID", "Attribute"}, "tblCorrection", JoinKind.LeftOuter),
    #"Expanded tblCorrection" = Table.ExpandTableColumn(Source, "tblCorrection", {"Value"}, {"tblCorrection.Value"}),
    #"Added Custom" = Table.AddColumn(#"Expanded tblCorrection", "Custom", each if [tblCorrection.Value] = " " or [tblCorrection.Value] = null then [Value] else [tblCorrection.Value]),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Value", "tblCorrection.Value"}),
    #"Pivoted Column" = Table.Pivot(#"Removed Columns", List.Distinct(#"Removed Columns"[Attribute]), "Attribute", "Custom")
in
    #"Pivoted Column"

If the problem is still not resolved, please provide detailed error information or the expected result you expect. Let me know immediately, looking forward to your reply.
Best Regards,
Winniz
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