upd

Strela/Services/SQLiteService.cs

@@ -7,7 +7,9 @@ namespace Strela.Services
     {
         public SQLiteService() => Database.EnsureCreated();
         public virtual DbSet<User> Users { get; set; }
-        
+        public virtual DbSet<DeviceItem> Devices { get; set; }
+        public virtual DbSet<DeviceType> DeviceTypes { get; set; }
+
 
         protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {