# Tags **Software** : [[02 - Tags/Software/Power Query]] **Functions** used : [[csv.Document]] [[Table.PromoteHeaders]] [[Table.SelectColumns]] [[List.LastN]] [[Table.ColumnNames]] [[Table.TransformColumns]] [[Table.AddColumn]] [[List.Sum]] [[Record.ToList]] [[Record.RemoveFields]] **Date** : 23-March-2026 # Description In this video i show you how to dynamically sum the last 3 (N) columns of a csv datset. Alot of little tricks here that you might find handy. # Video Link <iframe width="560" height="315" src="https://www.youtube.com/embed/0lSo-pTNiaA?si=ICrrI6RO3UA4RQNI" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe> [GITHUB File Link](https://github.com/jbotes/powerbiTutorials/blob/main/PQ_LastNTotal_Video.xlsx) # M-Query ```mquery let Source = Csv.Document(File.Contents("C:\test\us_stock_sales_2024.csv"),[Delimiter=",", Encoding=1252, QuoteStyle=QuoteStyle.None]), #"Promoted Headers" = Table.PromoteHeaders(Source, [PromoteAllScalars=true]), ColumnNames = Table.SelectColumns(#"Promoted Headers", {"StockCode"} & List.LastN(Table.ColumnNames(#"Promoted Headers"),3)), Types = Table.TransformColumns(ColumnNames, {"StockCode", Text.From}, Currency.From), #"Added Custom" = Table.AddColumn(Types, "Total", each List.Sum(Record.ToList(Record.RemoveFields(_, "StockCode"))), Currency.Type) in #"Added Custom" ``` ## Optional Tags **Tags** : **Technique** :