DeliveryAdminWindow is now able to look at deliveries

Elwig/Helpers/AppDbContext.cs

@@ -119,5 +119,12 @@ namespace Elwig.Helpers {
                 .ForEach(a => { if (a <= c + 10) c = a; });
             return c + 1;
         }
+
+        public async Task<WineQualLevel> GetWineQualityLevel(double kmw) {
+            return await WineQualityLevels
+                .Where(q => !q.IsPredicate && (q.MinKmw == null || q.MinKmw <= kmw))
+                .OrderBy(q => q.MinKmw)
+                .LastOrDefaultAsync();
+        }
     }
 }