Forum Discussion

dpbi's avatar
dpbi
Helper I
8 years ago
Solved

Distinct count loop in power query

Hi

I need to add custom column that  itterates over a column and count distinct values in a repeated fix range.

 

In this example, the ‘CustomColumn’ in the ‘Result Table’ calculates the number of distinct values in a range of 3 rows (for each row of ‘Column1’ in ‘Base Table’).

 

I know how to do that in DAX, however, I need Power Query solution.

Thanks.

 

Need Help
  • v-yulgu-msft's avatar
    v-yulgu-msft
    8 years ago

    Hi dpbi,

     

    let
    Source = Excel.Workbook(File.Contents("C:\xxxx\xxxx\Desktop\Sample Data.xlsx"), null, true),
    #"Base Table_Sheet" = Source{[Item="Base Table",Kind="Sheet"]}[Data],
    #"Promoted Headers" = Table.PromoteHeaders(#"Base Table_Sheet", [PromoteAllScalars=true]),
    #"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers",{{"Index", Int64.Type}, {"Column1", type text}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "DistinctPerIndex", (This) => List.Distinct(Table.SelectRows(#"Changed Type", each [Index] <= This[Index] and [Index] >= This[Index]-2)[Column1])),
    #"Expanded DistinctPerIndex" = Table.ExpandListColumn(#"Added Custom", "DistinctPerIndex"),
    #"Grouped Rows" = Table.Group(#"Expanded DistinctPerIndex", {"Index"}, {{"CountDistinct", each Table.RowCount(_), type number}, {"AllData", each _, type table}}),
    #"Expanded AllData" = Table.ExpandTableColumn(#"Grouped Rows", "AllData", {"Column1"}, {"AllData.Column1"}),
    #"Removed Duplicates" = Table.Distinct(#"Expanded AllData", {"Index"}),
    #"Renamed Columns" = Table.RenameColumns(#"Removed Duplicates",{{"AllData.Column1", "Column1"}})
in
    #"Renamed Columns"

     

    Best regards,

    Yuliana Gu

2 Replies

  • v-yulgu-msft's avatar
    v-yulgu-msft
    Microsoft Employee
    8 years ago

    Hi dpbi,

     

    let
    Source = Excel.Workbook(File.Contents("C:\xxxx\xxxx\Desktop\Sample Data.xlsx"), null, true),
    #"Base Table_Sheet" = Source{[Item="Base Table",Kind="Sheet"]}[Data],
    #"Promoted Headers" = Table.PromoteHeaders(#"Base Table_Sheet", [PromoteAllScalars=true]),
    #"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers",{{"Index", Int64.Type}, {"Column1", type text}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "DistinctPerIndex", (This) => List.Distinct(Table.SelectRows(#"Changed Type", each [Index] <= This[Index] and [Index] >= This[Index]-2)[Column1])),
    #"Expanded DistinctPerIndex" = Table.ExpandListColumn(#"Added Custom", "DistinctPerIndex"),
    #"Grouped Rows" = Table.Group(#"Expanded DistinctPerIndex", {"Index"}, {{"CountDistinct", each Table.RowCount(_), type number}, {"AllData", each _, type table}}),
    #"Expanded AllData" = Table.ExpandTableColumn(#"Grouped Rows", "AllData", {"Column1"}, {"AllData.Column1"}),
    #"Removed Duplicates" = Table.Distinct(#"Expanded AllData", {"Index"}),
    #"Renamed Columns" = Table.RenameColumns(#"Removed Duplicates",{{"AllData.Column1", "Column1"}})
in
    #"Renamed Columns"

     

    Best regards,

    Yuliana Gu

    • dpbi's avatar
      dpbi
      Helper I
      8 years ago

      Hi @ v-yulgu-msft

       

      Exactly what i needed.

      Thank you very much Yuliana for your kind help.

      Great support, very much appreciated!

      Best regards

      Dan