I have a table of parcels. Each parcel can have multiple land use types (not necesarily distinct). Those are stored in another table - so in the UseType table, a parcel can show up as wineyard, agriculture, wineyard and orchard.
To get to know how many usetypes I have for each parcel, so my approach was:
Unfortunately, several features in the UseType table have NULL in the column "usetype" - how can i exclude them from the count?