Filtering a table based on the maximum value of a column

[bkermen]

Hi,

I want to filter a table so that I keep those rows that have the maximum value in a column. For example, I have:

Name	Col 2	Col 3	Col 4	Revision no
A	..	..	..	0
A	..	..	..	1
A	..	..	..	2
B	..	..	..	0
B	..	..	..	1
C	..	..	..	0
D	..	..	..	0

After filtering; I want:

Name	Col 2	Col 3	Col 4	Revision no
A	..	..	..	2
B	..	..	..	1
C	..	..	..	0
D	..	..	..	0

Is there a simple way of avhieving this result?

[v-angzheng-msft · Accepted solution]

Hi, @bkermen 

Try this:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUTIEYiMgNgZiA6VYHYgoTMQErAImChMxBasAiTphNcEJqwnOWNW6YIrGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Name = _t, #"Col 2" = _t, #"Col 3" = _t, #"Col 4" = _t, #"Revision no" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Name", type text}, {"Col 2", type text}, {"Col 3", type text}, {"Col 4", type text}, {"Revision no", Int64.Type}}),

    
    T2=Table.Group(#"Changed Type", {"Name"}, {{"max", each List.Max([Revision no]), type nullable number}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"Name", "Revision no"}, T2, {"Name", "max"}, "Table (2)", JoinKind.LeftOuter),
    #"Expanded Table (2)" = Table.ExpandTableColumn(#"Merged Queries", "Table (2)", {"max"}, {"Table (2).max"}),
    #"Filtered Rows" = Table.SelectRows(#"Expanded Table (2)", each ([#"Table (2).max"] <> null)),
    #"Removed Columns" = Table.RemoveColumns(#"Filtered Rows",{"Table (2).max"})
in
    #"Removed Columns"

Result:

Please refer to the attachment below for details. Hope this helps.

Best Regards,
Community Support Team _ Zeon Zheng

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

[bkermen]

@smpa01 This seems to work only if the values in the other columns (Col 2-4) are identical. What I actually want to do is to filter the data in Power Query Editor so that only the filtered rows are in the data model. 

[smpa01]

@bkermen  you can use a measure like this

Measure = CALCULATE(MAX('Table'[Revision no]),ALLEXCEPT('Table','Table'[Name]))