Change blank by earliest text value per week

[joshua1990]

Hi all!

I have an archive with the weekly extract of our sales data in a table like this:

Archival Year-Week	Order	Year-Week	Value
2023-01	1	2023-01	5
2023-01	2	null	6

As you can see, it happens the is a "null" in the Year-Week column.

I would like to change the null to the earliest Year-Week, that is available within the same Archival Year-Week value.

How would you do that within PQ if the table has rows more than 50MM?

[v-cgao-msft · Accepted solution]

Hi @joshua1990 ,

Hope it helps.

let
  Source = Table.FromRows(
    Json.Document(
      Binary.Decompress(
        Binary.FromText("i45WMjIwMtY1MFTSUQJhBM9UKVYHWdYIiPNKc3KAlJlSbCwA", BinaryEncoding.Base64), 
        Compression.Deflate
      )
    ), 
    let
      _t = ((type nullable text) meta [Serialized.Text = true])
    in
      type table [#"Archival Year-Week" = _t, Order = _t, #"Year-Week" = _t, Value = _t]
  ), 
  #"Changed Type" = Table.TransformColumnTypes(
    Source, 
    {
      {"Archival Year-Week", type date}, 
      {"Order", Int64.Type}, 
      {"Year-Week", type date}, 
      {"Value", Int64.Type}
    }
  ), 
  Custom1 = Table.TransformColumns(
    #"Changed Type", 
    {
      "Year-Week", 
      each 
        if _ <> null then
          _
        else
          Table.Group(
            #"Changed Type", 
            {"Archival Year-Week"}, 
            {{"Min", each List.Min([#"Archival Year-Week"])}}
          )[Min]{0}
    }
  )
in
  Custom1

Best Regards,
Gao
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly. If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

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[ronrsnfld]

If your actual data is similar to what you show, simply select that column and Fill Down.