Transforming Data with M

[credencial]

Hi folks,

I have a table data:

I need create two more columns like this:

and fill in the START and END columns following the formula:

START = END OF PREVIOUS MONTH (in this case the month of september)

END = (START + ENTRANCE) - EXIT

The dates are varied, they can comprise several periods according to the user's parameter date filter. I always have the START number for the first month given through a "STARTDATE" measure DAX.

I imagine the path is to do in M, can you give me a light?

Thanks for any help.

[credencial]

Thanks for solution @v-stephen-msft. Perfect.

[mahoneypat]

Here's one way to do it in the query editor.  To see how it works, just create a blank query, open the Advanced Editor and replace the text there with the M code below.  Did you mean to do + Exit - Entrance, since the End date is before the Start date with the formula above?  You can adapt this, if so.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45Wyk8u0TcyUNJRMgURZgZKsTrRSnn5ZRBBCxBhaAQRTUlNhogawZTGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t, Entrance = _t, Exit = _t]),
    #"Added Custom" = Table.AddColumn(Source, "DateForCalc", each "1/"&[Date]),
    #"Changed Type" = Table.TransformColumnTypes(#"Added Custom",{{"Entrance", Int64.Type}, {"Exit", Int64.Type}, {"DateForCalc", type date}}),
    #"Added Custom1" = Table.AddColumn(#"Changed Type", "Start", each Date.EndOfMonth(Date.AddMonths([DateForCalc], -1)), type date),
    #"Added Custom2" = Table.AddColumn(#"Added Custom1", "End", each Date.AddDays([Start], [Entrance] - [Exit]), type date)
in
    #"Added Custom2"

Pat

[credencial]

Thanks @mahoneypat .

I tested your suggestion, but I didn't get the result. Maybe I didn't explain it right. I need this result:

[v-stephen-msft · Accepted solution]

Hi @credencial ,

Here is the whole M syntax:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WKk4t0DcyUNJRgiBDAwOlWJ1opfzkEoiwKYgwAysAiefll0HELUCEoRFcIiU1GSJhhKQhFgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t, Entrance = _t, Exit = _t, End = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type text}, {"Entrance", Int64.Type}, {"Exit", Int64.Type}, {"End", Int64.Type}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1, Int64.Type),
    #"Added Custom" = Table.AddColumn(#"Added Index", "Custom", each try #"Added Index" [End] {[Index] - 1} otherwise null),
    #"Filled Down" = Table.FillDown(#"Added Custom",{"End"}),
    #"Added Custom1" = Table.AddColumn(#"Filled Down", "Custom.1", each if [Index]=0 then [End] else [End]+List.Sum(List.Range(#"Filled Down"[Entrance],1,[Index]))-List.Sum(List.Range(#"Filled Down"[Exit],1,[Index]))),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom1",{"Custom"}),
    #"Added Custom2" = Table.AddColumn(#"Removed Columns", "Custom", each try #"Added Custom1" [Custom.1]{[Index] - 1} otherwise null),
    #"Removed Columns1" = Table.RemoveColumns(#"Added Custom2",{"Index", "End"}),
    #"Renamed Columns" = Table.RenameColumns(#"Removed Columns1",{{"Custom.1", "End"}, {"Custom", "Start"}})
in
    #"Renamed Columns"

The final result is this.

Best Regards,

Stephen Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.