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Anonymous's avatar
Anonymous
Not applicable
5 years ago
Solved

List accumulate in groups

Hi!! I need to get the previous value and sum with the current row, but for each group of index. if index = 1 then i need to get him like the example below. I find way to do using list.accumula...
Need Help
  • PhilipTreacy's avatar
    PhilipTreacy
    5 years ago

    Hi Anonymous 

    Please see this example file for solution Grouped Running Total in PQ

    Using a custom function and List.Generate you can create grouped running totals like this.

     

    Custom Function fxGroupedRunningTotal

     

     

    (values as list, grouping as list) as list =>

let
    GRTList = List.Generate
    ( 
        ()=> [ GRT = values{0}, i = 0 ],

        each [i] < List.Count(values),

        each try 
                 if grouping{[i]} = grouping{[i] + 1} 
                 then [GRT = [GRT] + values{[i] + 1}, i = [i] + 1]
                 else [GRT = values{[i] + 1}, i = [i] + 1]
        
             otherwise [i = [i] + 1]
    ,
        each [GRT]
    )
in
    GRTList

     

     

     

    This following query loads your data from a table and then calls the function, passing in the ID and Values columns.

     

     

    let
    Source = Excel.CurrentWorkbook(){[Name="SourceData"]}[Content],
    BufferedValues = List.Buffer(Source[Value]),
    BufferedGroup = List.Buffer(Source[ID]),

    RT = Table.FromColumns(
    {
      Source[ID], Source[Index], Source[Value],
      fxGroupedRunningTotal(BufferedValues, BufferedGroup)
    },
    {
      "ID",
      "Index",
      "Value",
      "Running Total"
    })
in
    RT

     

     

    Phil

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Jimmy801's avatar
Jimmy801
Community Champion
5 years ago

Hello Anonymous 

 

here maybe a straightforward solution

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("RczBDcAwCAPAXXinUoDSDhPl0Wb/HYppBA8/TrI9Bj3UiD2iNNtP8RxFBTl5Ft+9vXoytncytpbEVqtsEWjtJ+5JPEkRT+acHw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Index = _t, Value = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", type text}, {"Index", Int64.Type}, {"Value", Int64.Type}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"ID"}, {{"AllRows", (tbl)=> Table.AddColumn(tbl,"running total", (add)=> List.Sum(Table.SelectRows(tbl, each [Index]<= add[Index])[Value]))}}),
    #"Expanded AllRows" = Table.ExpandTableColumn(#"Grouped Rows", "AllRows", {"Index", "Value", "running total"}, {"Index", "Value", "running total"})
in
    #"Expanded AllRows"

 

Copy paste this code to the advanced editor in a new blank query to see how the solution works.

If this post helps or solves your problem, please mark it as solution (to help other users find useful content and to acknowledge the work of users that helped you)
Kudoes are nice too

Have fun

Jimmy