public int Delete(int id, byte[] timeStamp)
{
_db.Entry(new T {
Id = id, TimeStamp = timeStamp
}).State = EntityState.Deleted;
return(SaveChanges());
}
public int Delete(int id, byte[] timeStamp)
{
ctx.Entry <T>(new T()
{
Id = id, Timestamp = timeStamp
}).State = EntityState.Deleted;
return(SaveChanges());
}
private static void PrintAllInventory()
{
// Select all items from the Inventory table of AutoLot,
// and print out the data using our custom ToString()
// of the Car entity class.
using (var context = new AutoLotEntities())
{
foreach (Car c in context.Cars)
{
WriteLine(c);
}
foreach (Car c in context.Cars.SqlQuery(
"Select CarId,Make,Color,PetName as CarNickName from Inventory where Make=@p0", "BMW"))
{
WriteLine(c);
}
foreach (ShortCar c in context.Database.SqlQuery(typeof(ShortCar), "Select CarId,Make from Inventory"))
{
WriteLine(c);
}
foreach (Car c in context.Cars.Where(c => c.Make == "BMW"))
{
WriteLine(c);
}
WriteLine(context.Cars.Find(5));
foreach (Car c in context.Cars)
{
foreach (Order o in c.Orders)
{
WriteLine(o.OrderId);
}
}
foreach (Car c in context.Cars.Include(c => c.Orders))
{
foreach (Order o in c.Orders)
{
WriteLine(o.OrderId);
}
}
context.Configuration.LazyLoadingEnabled = false;
foreach (Car c in context.Cars)
{
context.Entry(c).Collection(x => x.Orders).Load();
foreach (Order o in c.Orders)
{
WriteLine(o.OrderId);
}
}
foreach (Order o in context.Orders)
{
context.Entry(o).Reference(x => x.Car).Load();
}
}
}
public static void UpdateCarRecord(int carId)
{
using (AutoLotEntities context = new AutoLotEntities()) {
Car carToUpdate = context.Cars.Find(carId);
if (carToUpdate != null)
{
Console.WriteLine("State Before Update: {0}", context.Entry(carToUpdate).State);
carToUpdate.PetName = "Sabrina";
Console.WriteLine("State After Update: {0}", context.Entry(carToUpdate).State);
context.SaveChanges();
}
}
}
private static void UpdateRecord(int carId)
{
using (var context = new AutoLotEntities())
{
var carToUpdate = context.Cars.Find(carId);
if (carToUpdate != null)
{
Console.WriteLine(context.Entry(carToUpdate).State);
carToUpdate.Color = "Blue";
Console.WriteLine(context.Entry(carToUpdate).State);
context.SaveChanges();
}
}
}
private static void UpdateRecord(int carId)
{
using (var context = new AutoLotEntities())
{
// Grab the car, change it, save!
Car carToUpdate = context.Cars.Find(carId);
if (carToUpdate != null)
{
WriteLine(context.Entry(carToUpdate).State);
carToUpdate.Color = "Blue";
WriteLine(context.Entry(carToUpdate).State);
}
}
}
private static void UpdateColor(int carId, string color)
{
WriteLine($"Update the Color to {color} for CarId {carId} ");
using (var context = new AutoLotEntities()) {
Car carToUpdate = context.cars.Find(carId);
if (carToUpdate != null)
{
WriteLine(context.Entry(carToUpdate).State);
carToUpdate.Color = color;
WriteLine(context.Entry(carToUpdate).State);
context.SaveChanges();
}
}
}
private static void UpdateRecord(int carld)
{
// Найти запись об автомобиле, подлежащую обновлению, по первичному ключу,
using (var context = new AutoLotEntities())
{
// Получить запись об автомобиле, обновить ее и сохранить!
Car carToUpdate = context.Cars.Find(carld);
if (carToUpdate != null)
{
WriteLine(context.Entry(carToUpdate).State);
carToUpdate.Color = "Blue";
WriteLine(context.Entry(carToUpdate).State);
context.SaveChanges();
}
}
}
/// <summary>
/// Find a car by carId and then update it.
/// </summary>
/// <param name="carId"></param>
private static void UpdateRecord(int carId)
{
using (var context = new AutoLotEntities())
{
// Grab the car, change it, save!
Inventory carToUpdate = context.Inventories.Find(carId);
WriteLine("UpdateRecord: Found " + carToUpdate);
if (carToUpdate != null)
{
WriteLine("Prior to update " + context.Entry(carToUpdate).State);
carToUpdate.Color = "Metallic Blue";
WriteLine("After update " + context.Entry(carToUpdate).State);
context.SaveChanges();
}
}
}
private static void GetAllCarOrdersExplicit()
{
using (var context = new AutoLotEntities())
{
context.Configuration.LazyLoadingEnabled = false;
foreach (Car c in context.Cars)
{
context.Entry(c).Collection(x => x.Orders).Load();
foreach (Order o in c.Orders)
{
WriteLine(o.OrderId);
}
}
foreach (Order o in context.Orders)
{
context.Entry(o).Reference(x => x.Car).Load();
}
}
}
public ActionResult Edit([Bind(Include = "CarId,Make,Color,PetName,Timestamp")] Inventory inventory)
{
if (ModelState.IsValid)
{
db.Entry(inventory).State = EntityState.Modified;
db.SaveChanges();
return(RedirectToAction("Index"));
}
return(View(inventory));
}
static void UpdateRecord(int carId)
{
//Найти запись об автомобиле по первичному ключу
using (var context = new AutoLotEntities())
{
Car carToUpdate = context.Cars.Find(carId);
if (carToUpdate != null)
{
WriteLine(context.Entry(carToUpdate).State);
carToUpdate.Color = "Red";
WriteLine(context.Entry(carToUpdate).State);
context.SaveChanges();
foreach (var item in context.Cars)
{
WriteLine(item);
}
}
}
}
public ActionResult Edit([Bind(Include = "CustId,FirstName,LastName,Timestamp")] Customer customer)
{
if (ModelState.IsValid)
{
db.Entry(customer).State = EntityState.Modified;
db.SaveChanges();
return(RedirectToAction("Index"));
}
return(View(customer));
}
public static void GetAllOrdersUsingExplicitLoading()
{
// efficient
using (AutoLotEntities context = new AutoLotEntities()) {
context.Configuration.LazyLoadingEnabled = false;
foreach (Car car in context.Cars)
{
context.Entry(car).Collection("Orders").Load();
foreach (Order order in car.Orders)
{
Console.WriteLine(order);
}
}
foreach (Order order in context.Orders)
{
context.Entry(order).Reference("Car").Load();
Console.WriteLine(order.Car);
}
}
}
//Added a helper UpdateRecord(int carId) to update values in DB.
private static void UpdateRecord(int carId)
{
using (var context = new AutoLotEntities())
{
//Find a specific car object which I want to delete, is found by primary key.
Car carToUpdate = context.Cars.Find(carId);
if (carToUpdate != null)
{
//EntityState before update
WriteLine(context.Entry(carToUpdate).State);
//Set a new value.
carToUpdate.Color = "Blue";
//EntityState after update object's value in carToUpdate.Color
WriteLine(context.Entry(carToUpdate).State);
//Save changes to the DB.
context.SaveChanges();
}
}
}
private static void RemoveRecord(int carld)
{
using (var context = new AutoLotEntities())
{
Car carToDelete = context.Cars.Find(carld);
if (carToDelete != null)
{
context.Cars.Remove(carToDelete);
if (context.Entry(carToDelete).State != EntityState.Deleted)
{
throw new Exception("Unable to delete the record");
}
context.SaveChanges();
}
}
}
private static void RemoveRecord(int carId)
{
// Find a car to delte by primary key
using (var context = new AutoLotEntities())
{
Car carToDelete = context.Cars.Find(carId);
if (carToDelete != null)
{
context.Cars.Remove(carToDelete);
// This code is purely demonstrative to show the entity state changed to Deleted
if (context.Entry(carToDelete).State != EntityState.Deleted)
{
throw new Exception("Unable to delete the record");
}
context.SaveChanges();
}
}
}
static void RemoveRecordUsingEntityState(int carId)
{
using (var context = new AutoLotEntities())
{
Car carToDelete = new Car {
CarId = carId
};
context.Entry(carToDelete).State = EntityState.Deleted;
try
{
context.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
WriteLine(ex);
}
}
}
private static void RemoveRecordUsingEntityState(int carId)
{
using (var context = new AutoLotEntities())
{
Car carToDelete = new Car()
{
CarId = carId
}; // create a new car entity, set CarId property with incoming param value
context.Entry(carToDelete).State = System.Data.Entity.EntityState.Deleted; // set the state for this car in the context to 'deleted'
try
{
context.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
WriteLine(ex);
}
}
}
public static void DeleteRecordByTracking(int carId)
{
using (AutoLotEntities context = new AutoLotEntities()) {
Car car = context.Cars.Find(carId);
if (car != null)
{
context.Cars.Remove(car);
}
if (context.Entry(car).State != EntityState.Deleted)
{
throw new Exception("Unable to delete record!");
}
else
{
Console.WriteLine("Deleted");
}
context.SaveChanges();
}
}
private static void RemoveRecord(int carId)
{
using (var context = new AutoLotEntities())
{
Car carToDelete = context.Cars.Find(carId);
if (carToDelete != null)
{
context.Cars.Remove(carToDelete);
// Этот код предназначен чисто для демонстрации того,
// что состояние сущности изменилось на Deleted.
if (context.Entry(carToDelete).State != EntityState.Deleted)
{
throw new Exception("Unable to delete the record");
}
context.SaveChanges();
}
}
}
public static void DeleteRecordByEntityState(int carId)
{
// If an instance with the same primary key is already being tracked, this method will fail,
// since you can’t have two of the same entities with the same primary key being tracked by
// the DbChangeTracker.
using (AutoLotEntities context = new AutoLotEntities()) {
Car carToDelete = new Car()
{
CarId = carId
};
context.Entry(carToDelete).State = EntityState.Deleted;
try {
context.SaveChanges();
Console.WriteLine("Deleted.");
} catch (DbUpdateConcurrencyException ex) {
Console.WriteLine(ex.Message);
}
}
}
static void RemoveRecord(int carId)
{
//Найти запись об автомобиле, подлежащую удалению, по первичному ключу.
using (var context = new AutoLotEntities())
{
//Проверить наличие записи
Car carToDelete = context.Cars.Find(carId);
if (carToDelete != null)
{
context.Cars.Remove(carToDelete);
//Этот код предназначен чисто для демонстрации того,
//что состояние сущности изменилось на Deleted.
if (context.Entry(carToDelete).State != EntityState.Deleted)
{
throw new Exception("Unable to delete this record");
}
context.SaveChanges();
}
}
}
private static void ExplicitLoading()
{
ForegroundColor = ConsoleColor.Blue;
WriteLine("-> Explicit loading:");
using (var context = new AutoLotEntities()) {
context.Configuration.LazyLoadingEnabled = false;
foreach (Car c in context.cars)
{
context.Entry(c).Collection(x => x.Orders).Load();
Write($"CarID-{c.CarId}, Count-{c.Orders.Count}");
foreach (Order o in c.Orders)
{
Write($" : <OrderID-{o.OrderId}>");
}
WriteLine();
}
}
}
//Added a helper RemoveRecordUsingEntityState(int carId) to delete records in DB by marking EntityState on an object which I want to delete, is found by carId.
private static void RemoveRecordUsingEntityState(int carId)
{
using (var context = new AutoLotEntities())
{
//Create a new Car object and assign a carId to CarId, which I want to delete in DB.
Car carToDelete = new Car()
{
CarId = carId
};
//Set EntityState of carToDelete object to Deleted.
//So far, I didn't trip to the DB, meaning good performance.
context.Entry(carToDelete).State = EntityState.Deleted;
try
{
context.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
WriteLine(ex);
}
}
}
private static void RemoveRecordUsingEntityState()
{
ForegroundColor = ConsoleColor.DarkCyan;
WriteLine($"=> Deleting Record Using Entity State");
int carId = AddNewRecord();
ForegroundColor = ConsoleColor.DarkCyan;
WriteLine($"CarID {carId} to delete");
using (var context = new AutoLotEntities()) {
Car carToDelete = new Car()
{
CarId = carId
};
context.Entry(carToDelete).State = EntityState.Deleted;
try {
context.SaveChanges();
} catch (DbUpdateConcurrencyException ex) {
WriteLine(ex.Message);
}
}
}
private static void PrintAllInventory()
{
// Select all items from the Inventory table of AutoLot,
// and print out the data using our custom ToString()
// of the Inventory entity class.
using (var context = new AutoLotEntities())
{
WriteLine("*** PrintAllInventory ***");
WriteLine("Using context");
foreach (Inventory c in context.Inventories)
{
WriteLine(c);
}
WriteLine("Using a sql command");
foreach (Inventory c in context.Inventories.SqlQuery("Select CarId,Make,Color,Name from Inventory where Make=@p0", "BMW"))
{
WriteLine(c);
}
WriteLine("Using LINQ filter Only BMWs");
foreach (Inventory c in context.Inventories.Where(c => c.Make == "BMW"))
{
WriteLine(c);
}
WriteLine("Using orders in inventories - nested object from EF");
foreach (Inventory c in context.Inventories)
{
foreach (Order o in c.Orders)
{
WriteLine(o);
}
}
WriteLine("Using any orders for those in inventory using LINQ include");
foreach (Inventory c in context.Inventories.Include(c => c.Orders))
{
foreach (Order o in c.Orders)
{
WriteLine(o);
}
}
WriteLine("Using no lazy loading and direct using Entry()");
context.Configuration.LazyLoadingEnabled = false;
foreach (Inventory c in context.Inventories)
{
context.Entry(c).Collection(x => x.Orders).Load();
foreach (Order o in c.Orders)
{
WriteLine(o);
}
}
}
}
public int Save(T entity)
{
_db.Entry(entity).State = EntityState.Modified;
return(SaveChanges());
}