Add Text to an Existing Column in Power Query

This snippet below will add the text "ABC" to all the values in the [name] column in an existing table.

StepName = Table.TransformColumns(
  Source,
  {
    {
      "name", 
      each 
        Text.Combine({"ABC",(_)}),
      type text
    }
  }
)

This works by using the Table.TransformColumns method and the _ underscore function that returns the value of the existing row. Match this with the each function to apply a function to each record of a list of records (ie a column) and you can do many things to that existing column of values.

This is really handy so that you don't have to add a column, rename the column and then remove the old column.

Before hand, if I wanted to simply add some text to the start of an existing column of text, I would do something like:

  AddColumn = Table.AddColumn(Source, "new_name", each "ABC" & [name]),
  RenameColumn = Table.RenameColumns(AddColumn,{{"name", "old_name"}, {"new_name", "name"}}),
  RemoveColumn = Table.RemoveColumns(RenameColumn,{"old_name"}),

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