In one table I have two columns of linked Parent/Child data which I need to then Merge with a second table.
I need to create an Index column to obtain unique record so I can merge the two tables.
These tables have around 300 000 records each so I need to use Power Query and don't want to use Excel.
I need an index column based on the parent and then re=starts index count for every unique child
Parent Child Index needed
123 AAA 1
123 AAA 2
123 BBB 1
234 CCC 1
234 CCC 2
234 CCC 3