Power query - How can i merge all columns except for column name "Custom"

Question

My power query table has an unknown number of columns upon refresh, all columns with type decimal except for a single column name "Custom" which is type Number. I want to be able to merge all columns except for the "Custom" column. I cannot select the columns and do it because in the next refresh the column names might be different

1. I first created a list to get all existing column names apart from "Custom" as follows

= List.Select(Table.ColumnNames(ConveretedtoDecimal), each _ <> "Custom")

This works and generates the correct list of column names

2. Then i tried the following (as suggested by Chat GPT), but it does not work

=Table.TransformColumns(ConvertedtoDecimal, {{"Custom", each Text.Combine(List.Transform(columnsToMerge, each Text.From(_)), ""), type text}})

Answer 1

If I understand correctly, and you want to combine these numeric columns as text strings with no separator, then you could use this snippet:

    #"Cols to Merge" = List.RemoveItems(Table.ColumnNames(#"Previous Step"),{"Custom"}),

//Change merge columns to text, then combine them with no delimiter
    #"Type Merge as Text" = Table.TransformColumnTypes(#"Previous Step",
                List.Transform(#"Cols to Merge", each {_, type text})),
                
    #"Merged Columns" = Table.CombineColumns(#"Type Merge as Text",
        #"Cols to Merge",
        Combiner.CombineTextByDelimiter("", QuoteStyle.None),"Merged")

• Set the data type of the decimal columns to text
• Then combine the columns with "" as the delimiter