Forum Discussion
Using Power Query M Formula, from within TABLE_A, count related rows in TABLE_B
From within [TRANSACTION], I need to, in the most efficient method possible, count the rows (there may be none) in [PERSON], via the field [PersonID]. I've searched, but, all the functions I've foun...
You could use Table.Rowcount(Table.SelectRows(TRANSACTION, each List.Contains(PERSON[PersonID], [PersonID])))