Add column similar to countif in Excel|Power Query|Excel Forum|My Online Training Hub

Hi,

Is it possible to add a custom column in PQ that looks at the values in another column and returns a value of 1 the first time the value is encountered but a value of 0 for any further instances?

For example I have a column that contains sales quotation numbers. There are multiple lines for each quotation so the quotation number is replicated on each line. In the custom column I just want to show 1 when the first line is counted but zero for the remaining lines. When I sum up the values in the custom column it will give me the unique number of quotes raised.

I know that I could achieve this by grouping rows or isolating the column and removing duplicates but ideally I would like to do it by adding a column so I can retain all of the rest of the data in the table.

Thanks

Bax