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tc5pt's avatar
tc5pt
Regular Visitor
7 years ago
Solved

Remove columns containing a certain value

I have various columns that have a date listed in one row, therefore they contain a "/". None of the other columns I need contain a backslash in any of the rows. I would like to delete the columns co...
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  • Nolock's avatar
    Nolock
    7 years ago

    Hi tc5pt,

    I've tried to integrate it into the code you mentioned earlier. Just replace all occurrences of "Source" with #"Promoted Headers" and it should work in your Excel file.

     

    let
    Source = Excel.Workbook(File.Contents("C: Source"), null, true),
    #"1_Sheet" = Source{[Item="1",Kind="Sheet"]}[Data],
    #"Promoted Headers" = Table.PromoteHeaders(#"1_Sheet", [PromoteAllScalars=true]),

// get columns which contains any slash among values
    ColumnsToRemove = 
        List.Select(
            // get a list of all columns
            Table.ColumnNames(#"Promoted Headers"),
            (columnName) =>
                let
                    // get all values of a columns
                    ColumnValues = Table.Column(#"Promoted Headers", columnName),
                    // go through values and stop when you find the first occurence of a text containing a slash
                    // if there is a value with a slash, return true else false
                    ContainsSlash = List.AnyTrue(List.Transform(ColumnValues, each Text.Contains(_, "/")))
                in
                    ContainsSlash
        ),
    // remove columns
    Result = Table.RemoveColumns(#"Promoted Headers", ColumnsToRemove)
in
    Result
Nolock's avatar
Nolock
Resident Rockstar
7 years ago

Hi tc5pt,

I'm just guessing: You have to replace all occurancies of PreviousStepName. In your case you have to replace it twice.

 

let 
    PreviousStepName = <THE NAME OF PREVIOUS STEP>,
    columnsToRemove = List.Select(Table.ColumnNames(PreviousStepName), each Text.StartsWith(_, "Var") or Text.Contains(_, "_prep")) 
in 
    Table.RemoveColumns(PreviousStepName, columnsToRemove)

But I suppose there can also be another problem because your code starts with "=". Please post the whole query to see that you use it correctly.

  • tc5pt's avatar
    tc5pt
    Regular Visitor
    7 years ago

    Thanks for your response Nolock 

     

    Where exactly do I enter this code? In the Advanced Editor? When I do that it gives me either Token Comma or Token Eof expected. I am not sure how to input this code.

    • Nolock's avatar
      Nolock
      Resident Rockstar
      7 years ago

      Hi tc5pt,

      jep, in the Advanced Editor. Please post your PowerQuery query (without data) and I will help you to integrate the code.

      The error message means that there is a comma missing or maybe one in the end of the code before the last IN or something similar.

      • tc5pt's avatar
        tc5pt
        Regular Visitor
        7 years ago

        Nolock 

        let
    Source = Excel.Workbook(File.Contents("C: Source"), null, true),
    #"1_Sheet" = Source{[Item="1",Kind="Sheet"]}[Data],
    #"Promoted Headers" = Table.PromoteHeaders(#"1_Sheet", [PromoteAllScalars=true])
in
    #"Promoted Headers"

        This is what is currently in my advanced editor. It also Changed Type by default but I deleted that step because there were over 100 columns and it created a huge block of code.

         

        How would I inject the code you gave?