Expand all Columns in a Table at once

[joshuac055]

I need to expand each one of these columns that each represents a file, but it will take forever to do that. Is there a way to expand all of these columns at once?

[dufoq3]

Hi @joshuac055, check this:

let
    TableA = #table({"4/4/24", "4/11/24", "4/18/24"}, {
        {#table({"A", "B"}, {{1,2}, {3,4}}),
        #table({"A", "B", "C"}, {{5,6,7}, {8,9,10}}),
        #table({"D", "E"}, {{15,16}, {17,18}})}
    }),
    Ad_Helper = Table.AddColumn(TableA, "Helper", each 1, Int64.Type),
    UnpivotedOtherColumns = Table.UnpivotOtherColumns(Ad_Helper, {"Helper"}, "Date", "Table"),
    Ad_ColNames = Table.AddColumn(UnpivotedOtherColumns, "ColNames", each Table.ColumnNames([Table]), type list),
    ExpandedTable = Table.ExpandTableColumn(Ad_ColNames, "Table", List.Distinct(List.Combine(Ad_ColNames[ColNames]))),
    RemovedColumns = Table.RemoveColumns(ExpandedTable,{"ColNames", "Helper"}),
    ChangedType = Table.TransformColumnTypes(RemovedColumns,{{"Date", type date}}, "en-US")
in
    ChangedType

[joshuac055]

I got the error below. I have 39 columns I need to expand and potentially more.

Expression.Error: 39 keys were specified, but 3 values were provided.
Details:
[List]