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Anonymous's avatar
Anonymous
Not applicable
2 years ago
Solved

Help with creating a function, multiple SelectRows and GroupBy

Hi,

 

I need help with creating a function. 

 

This is my sample data:

 

session_startsession_userDaily_sum
9/20/2023Person 14
9/22/2023Person 15
9/25/2023Person 18
9/23/2023Person 23
9/25/2023Person 25
9/26/2023Person 24
9/27/2023Person 27

 

I need to find out the session_start date when the sum of each of the session_user goes below 10, calculated backwards from today.
In the sample data calculated from today (9/28/2023) backwards for Person 1 the date when the sum of Daily_sum values goes below 10 is 9/23/2023 (because 9/22/2023 adds 5)  and Person 2's 9/27/2023 (because 9/26/2023 adds 4). I also need to be able to set how many days into the past the data is calculated.

I figured that I need to make the following two steps multiple times. First select the data that are in the past n days: (here 10 days) Table.SelectRows(Source, each Date.IsInPreviousNDays([session_start], 10)).


Then group those by "session_user":
Table.Group(Custom, {"session_user"}, {{"Sum", each List.Sum([Daily_sum]), type nullable number}}).

 

Then I need to select the rows from the data that are in the past n - 1 days. Then group those by "session_user" and so on until today.

 

I was able to create a custom function that finds the value how many loops it takes for any of the values for session_users is below 10.

 

Here is the function:

 

 

 

 

let
  Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WKk4tLs7Mz4svLkksKlHSgfNLi1OLgFyXxMycyvji0lylWJ1oJUt9IwMgMjIGygSkFhXn5ykYApkmMEkjLJKmMElTLJIWMEljNEkjINMYl04jZGPNsEjCHWSORdJcKTYWAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t, Column2 = _t, Column3 = _t]),
  #"Promoted headers" = Table.PromoteHeaders(Source, [PromoteAllScalars = true]),
  #"Changed column type" = Table.TransformColumnTypes(#"Promoted headers", {{"session_start", type date}, {"session_user", type text}, {"Daily_sum", Int64.Type}}),


    CustomFunction = (n as number) as table =>
        let
            FilteredRows = Table.SelectRows(#"Changed column type", each Date.IsInPreviousNDays([session_start], n)),
            GroupedRows = Table.Group(FilteredRows, {"session_user"}, {{"Sum", each List.Sum([Daily_sum]), type nullable number}}),
            Result = if List.Min(GroupedRows[Sum]) < 10 then Table.AddColumn(GroupedRows, "Final N Value", each n) else @CustomFunction(n-1)
        in
            Result,
    FinalResult =
CustomFunction(10)
in
    FinalResult

 

 

 

 

 

 Here is the result at the moment:

The function has stopped because Person 1's sum is less than 10 but at the same time I need to find out when Person 2's sum goes below 10.

 

How can I achieve this?

  • Anonymous's avatar
    Anonymous
    2 years ago

    Hi Anonymous ,

    let
      Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WstQ3MgAiI2MlHaWA1KLi/DwFQyDTRClWByxphEXSFCZpikXSAiZpjCZpBGQa49JphGysGRZJuIPMsUiaK8XGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [session_start = _t, session_user = _t, Daily_sum = _t]),
        #"Changed column type" = Table.TransformColumnTypes(Source, {{"session_start", type date}, {"session_user", type text}, {"Daily_sum", Int64.Type}}),
    
      CustomFunction = (user as text, n as number) as table =>
        let
          FilteredRows = Table.SelectRows(#"Changed column type", each [session_user] = user and Date.IsInPreviousNDays([session_start], n)),
          GroupedRows = Table.Group(FilteredRows, {"session_user"}, {{"Sum", each List.Sum([Daily_sum]), type nullable number}}),
          Result = if List.Min(GroupedRows[Sum]) < 10 then Table.AddColumn(GroupedRows, "Final N Value", each n) else @CustomFunction(user, n-1)
        in
          Result,
    
      Users = List.Distinct(#"Changed column type"[session_user]),
      Results = List.Transform(Users, each CustomFunction(_, 10)),
      FinalResult = Table.Combine(Results)
    in
      FinalResult

    Output:

    If I've misunderstood your question, feel free to contact me.

     

    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

1 Reply

  • Anonymous's avatar
    Anonymous
    Not applicable

    Hi Anonymous ,

    let
      Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WstQ3MgAiI2MlHaWA1KLi/DwFQyDTRClWByxphEXSFCZpikXSAiZpjCZpBGQa49JphGysGRZJuIPMsUiaK8XGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [session_start = _t, session_user = _t, Daily_sum = _t]),
        #"Changed column type" = Table.TransformColumnTypes(Source, {{"session_start", type date}, {"session_user", type text}, {"Daily_sum", Int64.Type}}),
    
      CustomFunction = (user as text, n as number) as table =>
        let
          FilteredRows = Table.SelectRows(#"Changed column type", each [session_user] = user and Date.IsInPreviousNDays([session_start], n)),
          GroupedRows = Table.Group(FilteredRows, {"session_user"}, {{"Sum", each List.Sum([Daily_sum]), type nullable number}}),
          Result = if List.Min(GroupedRows[Sum]) < 10 then Table.AddColumn(GroupedRows, "Final N Value", each n) else @CustomFunction(user, n-1)
        in
          Result,
    
      Users = List.Distinct(#"Changed column type"[session_user]),
      Results = List.Transform(Users, each CustomFunction(_, 10)),
      FinalResult = Table.Combine(Results)
    in
      FinalResult

    Output:

    If I've misunderstood your question, feel free to contact me.

     

    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