I have a single column table of customer account numbers and a main table containing 400,000 records pulling from an access database. I want to remove all records from the table where the customer account number can be found in the single column table.
The merge query capability in power query allows me to return only the records where there is a match on the customer list (in addition to a variety of other variations on this theme) but I would like to know whether there is a way to invert this so that I return all records where the customer number does not appear in this list.
I have achieved this already by using the List.Contains function and adding a custom column to identify the rows to exclude and then filtering them out, but I think this is severely impacting the performance of my workbook. Refreshing the table that initially has 400,000 rows prior to this series of transformations takes a very long time, and all queries that depend on this table then also take a long time to refresh.
Thank you
