In QGIS I created a one-to-many relation between a polygon layer and a non-geometry table, so it has multiple lines for each feature in the polygon layer. My question now is how can I count how many rows were related?
For example, let's suppose the table has 44.000 rows, and I have 26.000 polygon features (each with its own id). If it were a one-to-one relation I know it would've been 26.000 relations, but since it's a one-to-many a polygon can have 2 or more rows related with it. How could I know how many rows were related then?