DAX Function

Hi webi2pbi 

1.You can put the following code to Advanced Editor in powr query.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjcwNDQ0UNJRMja0MDQ0NzAwsgRyPBx9nICUkVKsTrQSRBIkZWFgAFIaFezoiyZrYA7S5uYaFAKkkMTNzMyxilsYmeMwCGwDmgYTDINiAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Specification = _t, Material = _t, #"Mat Type" = _t, Standard = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Specification", Int64.Type}, {"Material", Int64.Type}, {"Mat Type", type text}, {"Standard", Int64.Type}}),
    #"Filled Down" = Table.FillDown(#"Changed Type",{"Specification"}),
    #"Grouped Rows" = Table.Group(#"Filled Down", {"Specification"}, {{"Count", each _, type table [Specification=nullable number, Material=nullable number, Mat Type=nullable text, Standard=nullable number]}}),
    #"Added Custom" = Table.AddColumn(#"Grouped Rows", "Custom", each if List.Contains([Count][Mat Type],"ZSAM") then List.Max([Count][Standard]) else null),
    #"Expanded Count" = Table.ExpandTableColumn(#"Added Custom", "Count", {"Material", "Mat Type", "Standard"}, {"Material", "Mat Type", "Standard"})
in
    #"Expanded Count"

 2.You can create a column in table

Column =
VAR a =
    COUNTROWS (
        FILTER (
            'Table (2)',
            [Specification] = EARLIER ( 'Table (2)'[Specification] )
                && [Mat Type] = "ZSAM"
        )
    )
VAR b =
    MAXX (
        FILTER (
            'Table (2)',
            [Specification] = EARLIER ( 'Table (2)'[Specification] )
                && [Mat Type] = "ZSAM"
        ),
        [Standard]
    )
RETURN
    IF ( a > 0, b )

Best Regards!

Yolo Zhu

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