Help with transposing rows if column is the same.

[RapidRestore]

I would like to use Power Query to transform the table below (Before) to the (After).

The idea would be to transpose rows (Sub Invoice#, Task Descriton, Price) to additional columns if the (InvoiceNumber) column matches.

Before

Before

After

Thank you!

[wdx223_Daniel · Accepted solution]

=let col=Table.ColumnNames(Before) in Table.Combine(Table.Group(Before,"InvoiceNumber",{"n",each Table.FromRows({{[InvoiceNumber]{0}}&List.Combine(Table.ToRows(Table.SelectColumns(_,List.Skip(col))))},List.TransformMany({0..Table.RowCount(_)-1},each if _=0 then col else List.Skip(col),(x,y)=>if x=0 then y else y&" - "& Text.From(x+1)))})[n])