When I 'Unpivot' certain columns, it alters the data in the whole model? - even unselected columns

[Anonymous]

My spreadsheet contains a lot of dates as colums and I want to 'unpivot' these so they collapse into one column. When I select the columns that I want to be affected, the whole spreadhseet ends up changing, even the columns I did not select. 

I can't figure out what is causing the change? I worked on an older version of this spreadsheet and never had this problem. 

I have attached two images showing a before and after.

The dates to the right are what I want to condense into one column. the information to the left I can organise properly in the visualisation. 

I am selecting the columns to the left as there is only about 7/8 and then doing Transform>Unpivot Other Columns.

But this changes the whole spreadsheet as you can see below.

Any tips would be much appreciated!

Cheers

[v-diye-msft · Accepted solution]

Hi @Anonymous 

Please note that definition of unpivot column:

If you'd like to merge several columns into one column,I'd like to suggest below M code: (Select Date1&2&3, then unpivot)

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WSlTSUTIEYiMDQ0t9Q30jIBOEYnWilZJAwhA+VNYYJpUMZBhDlcJlTZRiYwE=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [Column1 = _t, Column2 = _t, Date1 = _t, Date2 = _t, Date3 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}, {"Column2", Int64.Type}}),
    #"Unpivoted Columns" = Table.UnpivotOtherColumns(#"Changed Type", {"Column1", "Column2"}, "Attribute", "Value"),
    #"Filtered Rows" = Table.SelectRows(#"Unpivoted Columns", each [Value] <> null and [Value] <> "")
in
    #"Filtered Rows"