コード例 #1
0
        private static void DynamicLinq(EntitiesModel context)
        {
            // strongly typed dynamic LINQ
            Console.WriteLine("Dynamic strongly typed LINQ Where:");
            var query1 = context.Cars.Where("CarYear < @0", 2000).ToList();
            Console.WriteLine("Car\tCategory");
            foreach (var car in query1)
            {
                Console.WriteLine("{0}\t{1}", car.CarID, car.Category.CategoryName);
            }

            // weakly typed dynamic LINQ with projection
            Console.WriteLine("Dynamic weakly typed LINQ Where and Select:");
            var objList = context.GetAll("OpenAccessModel9.Car").Where("CarYear < @0", 2000)
                .Select("new (CarID as Id, CarYear)")
                .Cast<object>().ToList();
            foreach (object objCar in objList)
            {
                Console.WriteLine(objCar);
            }
        }
コード例 #2
0
        private static void BulkDelete(EntitiesModel context)
        {
            // avoid showing the INSERT statements that populate the data
            context.Log = null;

            for (int i = 0; i < 10; i++)
            {
                Car car = new Car() { Make = "BMW", Model = "1020", CarYear = 2018, Available = true, CategoryID = 1, TagNumber = i.ToString()};
                context.Add(car);
            }
            context.SaveChanges();

            // show the delete statements
            context.Log = Console.Out;

            var query = context.GetAll<Car>().Where(c => c.CarYear > DateTime.Now.Year);
            int deleted = query.DeleteAll();
            Console.WriteLine("Deleted cars: {0}", deleted);
        }
コード例 #3
0
        private static void BulkUpdate(EntitiesModel context)
        {
            string tooOldName = "Too old";
            Category tooOldCategory = context.Categories.FirstOrDefault(c => c.CategoryName == tooOldName);
            if (tooOldCategory == null)
            {
                tooOldCategory = new Category();
                tooOldCategory.CategoryName = tooOldName;
                context.Add(tooOldCategory);
                context.SaveChanges();
            }

            var query = context.GetAll<Car>().Where(c => c.CarYear < 2000);

            int updated = query.UpdateAll(u => u.Set(c => c.Category, c => tooOldCategory)
                                                .Set(c => c.Available, c => false));

            Console.WriteLine("Updated cars: {0}", updated);
        }