Calculate the highest date value for people with the same ID.

[Adn1]

Hi All,

I want to create a new column in my table.

This column must calculate the highest date from the "END_DATE" column for lines of peoples that have the same "ID".

This is an example of how the table should work:

NAME	ID	END_DATE	New Column (Highest Date)
Ana	1	24/01/2023	24/01/2023
Gustav	1	01/01/2023	24/01/2023
Louis	35	10/02/2022	10/02/2022
Gabe	35	10/01/2022	10/02/2022

[tackytechtom · Accepted solution]

Hi @Adn1 ,

How about this:

Before:

After:

Here the code in Power Query M that you can paste into the advanced editor (if you do not know, how to exactly do this, please check out this quick walkthrough). The idea is to join the query from after the grouping (calculating MaxDate per ID) with the original query before the grouping:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcsxLVNJRUjAEEkYm+gaG+kYGRsZKsTrRSu6lxSWJZTBJoAyypE9+aWYxSM7YFEgaGugbGIEkjSA6E5NSUeQMoXKxAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [NAME = _t, ID = _t, END_DATE = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"NAME", type text}, {"ID", Int64.Type}, {"END_DATE", type date}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"ID"}, {{"MaxDate", each List.Max([END_DATE]), type nullable date}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"ID"}, #"Grouped Rows", {"ID"}, "Grouped Rows", JoinKind.LeftOuter),
    #"Expanded Grouped Rows" = Table.ExpandTableColumn(#"Merged Queries", "Grouped Rows", {"MaxDate"}, {"MaxDate"})
in
    #"Expanded Grouped Rows"

Let me know if this helps 🙂

/Tom
https://www.tackytech.blog/
https://www.instagram.com/tackytechtom/

[Adn1]

thanks!