Modelo de columnas calculadas

Hola @lucasaliba04

puedes hacerlo muy fácil con Power Query de la siguiente manera:

// RulesTable
let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("Xc65CcAwEATAXg6cKbjVr9BuQ6j/NrRgsBeFk82cdj/usGDwy1Z4HekoTnQSZzqLC13Ela7iRjdxp7t40OM3nBYePRw9fL21AQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Username = _t, #" Discount" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Username", type text}, {" Discount", Percentage.Type}})
in
    #"Changed Type"

// SourceTable
let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("Xc0xDsAgDEPRu2RmiBOg7dheA3H/a5CqUmUy+g3+Y8j9qEKKNFWVWT6wgM7gAZWhBjjtFtto99hoBMf7wHDm6JWi0BQF9ihsj8L/y7kA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Username = _t, #" Sales" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Username", type text}, {" Sales", Int64.Type}})
in
    #"Changed Type"

// CalculationTabel
let
    Source = Table.NestedJoin(RulesTable, {"Username"}, SourceTable, {"Username"}, "Calculation Table", JoinKind.LeftOuter),
    #"Expanded Calculation Table" = Table.ExpandTableColumn(Source, "Calculation Table", {" Sales"}, {" Sales"}),
    #"Added Custom" = Table.AddColumn(#"Expanded Calculation Table", "Sale post Discount", each [#" Sales"] - [#" Sales"] * [#" Discount"], type number)
in
    #"Added Custom"

Con saludos amables desde la ciudad donde la leyenda del 'Pied Piper de Hamelin' está en casa
FrankAT (Orgulloso de ser un Datanaut)