Misnamed column in Power Query

[todlad52]

I set up three tiny csv files so that I can combine them using power query in Excel. they are very simple files with column headers named First, Second, Third, Fourth. However, I deliberately made an error in file 3 and called the Second column Sceond. When I completed Get Data, From File, From Folder, the Second column contained the correct data from file 1 and file 2 but null entries for file 3 ... exactly as I expected. The problem is that I had expected to see the Sceond column as well but with null entries for files 1 and 2 and the correct values for file three but that column isn't included at all. Is this a change in Power Query? When did it happen?

Duncan

[Anonymous · Accepted solution]

Hi @todlad52 ,

In this step, the column names are chosen from the default first file, so there will be no "sceond" column after the expansion.

You can add a step to get all the column names:

Replace the previous list.

Output:

let
    Source = Folder.Files("C:\Users\xxx\Desktop\test"),
    #"Filtered Hidden Files1" = Table.SelectRows(Source, each [Attributes]?[Hidden]? <> true),
    #"Invoke Custom Function1" = Table.AddColumn(#"Filtered Hidden Files1", "Transform File", each #"Transform File"([Content])),
    #"Renamed Columns1" = Table.RenameColumns(#"Invoke Custom Function1", {"Name", "Source.Name"}),
    #"Removed Other Columns1" = Table.SelectColumns(#"Renamed Columns1", {"Source.Name", "Transform File"}),
    Custom1 = Table.ColumnNames ( Table.Combine ( #"Removed Other Columns1"[Transform File] ) ),
    #"Expanded Table Column1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File", Custom1),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded Table Column1",{{"Source.Name", type text}, {"First", Int64.Type}, {"Second", Int64.Type}, {"Third", Int64.Type}, {"Fourth", Int64.Type}})
in
    #"Changed Type"

Best Regards,
Gao
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly. If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

How to get your questions answered quickly --  How to provide sample data in the Power BI Forum

[todlad52]

Thank you Gao, that's a very comprehensive answer. I understand your comments and will be able to explain them fully in future!

Best wishes

Duncan