Rename Nested Tables Based on Condition

[JNB3]

Hello. I have a column named "Custom" which has nested tables, and I would like to conditionally rename the columns within the nested tables using the Text.Contains function. I thought my code below would achieve this, but it will only modify the parent column "Custom" rather than modifying the nested tables within. Thanks in advance for your time and help.

= let

Source = #"Added Custom",

RenamedColumns = Table.TransformColumnNames(Source, each if Text.Contains(_, "back", Comparer.OrdinalIgnoreCase)

then Text.Replace(_, _, "Back")  else _)

in RenamedColumns

[OwenAuger · Accepted solution]

Hi @JNB3 

You need to use Table.TransformColumns to apply the same transformation to each nested table within the Custom column.

On way to do this, is to first create a function that is similar to your RenamedColumns step (I called this RenameFunction), then apply this function using Table.TransformColumns in the ApplyRenameFunction step below.

let

  // Define a function that will be applied to each nested table
  RenameFunction = each Table.TransformColumnNames(
    _,
    each
      if Text.Contains(_, "back", Comparer.OrdinalIgnoreCase) then
        Text.Replace(_, _, "Back")
      else
        _
  ),
  // Source table
  Source = #"Added Custom",
  // Apply the function to each nested table in the Custom column
  ApplyRenameFunction = Table.TransformColumns(Source, {{"Custom", RenameFunction}})
in
  ApplyRenameFunction

Does this work for you?

Regards

[JNB3]

Thank you so much! This worked perfectly! Thanks again!