private static void ConcurrentTest()
{
using (var context1 = new BikeRentalContext())
using (var context2 = new BikeRentalContext())
{
var user1 = context1.Users.Find(1);
user1.PhoneNumber = "555-555-555";
var user2 = context2.Users.Find(1);
user2.PhoneNumber = "777-777-777";
// Different order
context2.SaveChanges();
// Some longer break, just for demo purpose - coffee break
Thread.Sleep(5000);
try
{
context1.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
WriteLine("Hey man, your coffee caused an exception");
var entry = ex.Entries.Single();
entry.Reload();
entry.Entity.Dump("Somebody has just saved the following user:");
}
}
}
public void DistributedTransactionScope()
{
// System.Transactions
using (var transaction = new TransactionScope())
{
var user = new User {
FirstName = "Janusz", Discount = 40, PhoneNumber = "111-222-333", Parameters = new Parameters {
P1 = 123, P2 = 345
}
};
using (var firstContext = new BikeRentalContext())
{
firstContext.Users.Add(user);
firstContext.SaveChanges();
}
using (var secondContext = new BikeRentalContext())
{
secondContext.Users.Add(user);
secondContext.SaveChanges();
}
// Set transaction flag ONLY. Changes are not commited.
transaction.Complete();
}
}
private static void ConcurrentWithRowVersionTest()
{
using (var context1 = new BikeRentalContext())
using (var context2 = new BikeRentalContext())
{
var station1 = context1.Stations.Find(1);
station1.Name = "Cmc";
var station2 = context2.Stations.Find(1);
station2.Name = "Lmc";
// Different order
context2.SaveChanges();
// Some longer break, just for demo purpose - coffee break
Thread.Sleep(5000);
try
{
context1.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
WriteLine("Hey man, your coffee caused an exception");
var entry = ex.Entries.Single();
entry.Reload();
entry.Entity.Dump("Somebody has just saved the following station:");
}
}
}
private static void AddVehiclesTest()
{
using (var context = new BikeRentalContext())
{
var bike = new Bike
{
BikeType = BikeType.City,
Color = "red",
Number = "B005"
};
var bike2 = new Bike
{
BikeType = BikeType.Moutain,
Color = "yellow",
Number = "B006"
};
var scooter = new Scooter
{
Color = "yellow",
Number = "S001",
EngineCapacity = 100
};
context.Vehicles.Add(bike);
context.Vehicles.Add(bike2);
context.Vehicles.Add(scooter);
context.SaveChanges();
}
}
private static void AddUser(string name, int discount)
{
var user = new User
{
FirstName = name,
LastName = $"N_{DateTime.Now.Hour}_{DateTime.Now.Minute}",
Discount = discount,
PhoneNumber = "123123123",
Parameters = new Parameters {
P1 = DateTime.Now.Minute, P2 = DateTime.Now.Millisecond
}
};
using (var dbContext = new BikeRentalContext())
{
try
{
dbContext.Users.Add(user);
dbContext.SaveChanges();
}
catch (Exception exception)
{
throw;
}
}
}
private static void ExecuteSpTest()
{
var proc = @"
create procedure uspDeleteBike(@BikeId int)
as begin
delete from [rentals].[Vehicles] where [VehicleId] = @BikeId;
end
";
using (var context = new BikeRentalContext())
{
context.Bikes.Add(new Bike
{
BikeType = BikeType.City,
Color = "Test",
Number = "B123"
});
context.SaveChanges();
context.Bikes.ToList().Dump();
var bikeToDelete = context.Bikes.FirstOrDefault(x => x.Number == "B123");
if (bikeToDelete != null)
{
var idParameter = new SqlParameter("BikeId", bikeToDelete.VehicleId);
context.Database.ExecuteSqlCommand("uspDeleteBike @BikeId", idParameter);
context.SaveChanges();
context.Bikes.ToList().Dump();
}
}
}
public void StorageTest()
{
//
// To enable automatic storage procedures there is a need to configure object:
// MapToStoredProcedures();
//
using (var context = new BikeRentalContext())
{
var station = new Station()
{
Address = "jakis adres",
Name = "stacjaX",
Location = new Location {
Latitude = 1, Longitude = 1
}
};
context.Stations.Add(station);
try
{
context.SaveChanges();
}
catch (System.Exception exception)
{
throw;
}
}
}
private static void AddStations(int count)
{
var stations = new List <Station>();
for (int i = 0; i < count; i++)
{
var station = new Station
{
Name = $"Stacja_{i}",
Address = $"Adres_{i}_{DateTime.Now.Hour}_{DateTime.Now.Minute}",
Location = new Location {
Latitude = DateTime.Now.Millisecond, Longitude = DateTime.Now.Millisecond
},
Capacity = 10,
IsActive = true
};
stations.Add(station);
}
using (var dbContext = new BikeRentalContext())
{
dbContext.Database.Exists();
dbContext.Stations.AddRange(stations);
try
{
dbContext.SaveChanges();
}
catch (Exception exception)
{
throw;
}
}
}
private static void AddUserStateTest()
{
var user = new User
{
FirstName = "Marcin",
LastName = $"N_{DateTime.Now.Hour}_{DateTime.Now.Minute}",
Discount = 40,
PhoneNumber = "123456789"
};
using (var dbContext = new BikeRentalContext())
{
try
{
// Add or update - own:
// dbContext.Users.Any(u => u == user); // only bool
// // performance best: Find().
dbContext.Entry(user); // State: Detached.
dbContext.Users.Add(user); // Add user to context.
dbContext.Entry(user); // State: Added.
dbContext.SaveChanges(); // Save context changes.
dbContext.Entry(user); // State: Unchanged.
dbContext.Users.Remove(user); // Remove user.
dbContext.Entry(user); // State: Deleted.
dbContext.SaveChanges(); // Save context changes.
dbContext.Entry(user); // State: Detached.
}
catch (Exception exception)
{
throw;
}
}
}
public void StorageProceduresTest()
{
/*
*
* CREATE PROCEDURE uspDeleteBike(@BikeId int)
* AS BEGIN
* DELETE FROM [rentals].[Vehicles] WHERE [VehicleId] = @BikeId
* END
*
*/
Console.Write("Enter Bike ID to delete: ");
var bikeId = Console.ReadLine();
var bikeIdParameter = new SqlParameter("@BikeId", bikeId);
// Output parameter.
// var outputParameter = new SqlParameter
// {
// Direction = System.Data.ParameterDirection.Output
// };
using (var context = new BikeRentalContext())
{
context.Database.ExecuteSqlCommand("uspDeleteBike @BikeId", bikeIdParameter);
}
}
private static void TryLoadingNonExistentBikeTest()
{
using (var context = new BikeRentalContext())
{
var bike = context.Bikes.Find(15); // checking how non existent row will be retrieved
// no exception
}
}
private static void UpdateUserViaSpTest()
{
using (var context = new BikeRentalContext())
{
var user = context.Users.First();
user.FirstName = "Johnny";
context.SaveChanges();
}
}
private static void SqlUpdateWithParamUnsafeTest(string color)
{
string sql = $"update[rentals].[Vehicles] set [IsActive] = 0 where [Color] = '{color}';";
using (var context = new BikeRentalContext())
{
context.Database.ExecuteSqlCommand(sql);
}
}
private static void SqlUpdateTest()
{
string sql = "update[rentals].[Vehicles] set [IsActive] = 0;";
using (var context = new BikeRentalContext())
{
context.Database.ExecuteSqlCommand(sql);
}
}
private static void DeserializeParametersTest()
{
using (var context = new BikeRentalContext())
{
foreach (var station in context.Stations.Where(x => x.SerializedParameters != null))
{
station.Parameters.Dump();
}
}
}
private static void SqlUpdateWithParamTest(string color)
{
string sql = $"update[rentals].[Vehicles] set [IsActive] = 0 where [Color] = @pColor;";
var colorParameter = new SqlParameter("pColor", color);
using (var context = new BikeRentalContext())
{
context.Database.ExecuteSqlCommand(sql, colorParameter);
}
}
private static void GetVehiclesTest()
{
using (var context = new BikeRentalContext())
{
foreach (var v in context.Vehicles)
{
WriteLine($"{v.Number}, {v.GetType().FullName}");
}
}
}
private static void GetSqlTest()
{
string sql = $"SELECT * FROM [rentals].[Vehicles] where [Color] like 'r%' and Discriminator = 'Bike';";
using (var context = new BikeRentalContext())
{
var bikes = context.Database.SqlQuery <Bike>(sql);
bikes.ToList().Dump();
}
}
private static void GetVehiclesTest()
{
using (var context = new BikeRentalContext())
{
var vehicles = context.Vehicles;
foreach (var vehicle in vehicles)
{
Console.WriteLine(vehicle.ToString());
}
}
}
private static void DeleteUserTest()
{
using (var context = new BikeRentalContext())
{
var user = context.Users.Find(1);
WriteLine(context.Entry(user).State);
context.Users.Remove(user);
WriteLine(context.Entry(user).State);
context.SaveChanges();
}
}
private static void SelectTest()
{
using (var context = new BikeRentalContext())
{
var vehicles = context.Vehicles.Select(x => new { x.Color, x.Number });
foreach (var v in vehicles)
{
WriteLine(v);
}
WriteLine(vehicles.ToString());
}
}
private static void UpdateParametersTest()
{
using (var context = new BikeRentalContext())
{
var user = context.Users.Find(25);
user.Parameters = new Parameters {
P1 = DateTime.Now.Minute, P2 = DateTime.Now.Millisecond
};
context.Entry(user).State = EntityState.Modified; // Property is ignored - force modification.
context.SaveChanges();
}
}
private static void GetRentalsNoLazyLoadingTest()
{
using (var context = new BikeRentalContext())
{
var rentals = context.Rentals
.ToList();
foreach (var r in rentals)
{
// Throws exception
WriteLine($"{r.DateFrom} - {r.DateTo}: {r.User.LastName}");
}
}
}
private static void GetRentalsIncludeViaStringTest()
{
using (var context = new BikeRentalContext())
{
var rentals = context.Rentals
.Include("User") // Prone to typos and poor refactoring
//.Include("User.Parameters") // In case of chained references
.ToList();
foreach (var r in rentals)
{
WriteLine($"{r.DateFrom} - {r.DateTo}: {r.User.LastName}");
}
}
}
private static void SyntaxTest()
{
using (var context = new BikeRentalContext())
{
var query = (from vehicle in context.Vehicles
where vehicle.Color == "Red"
orderby vehicle.Number
select vehicle)
.Where(x => x.Number.Contains("1"));
WriteLine(query.ToString());
var unionDistinct = query.Distinct();
unionDistinct.ToList().Dump();
}
}
private static void GetRentalsIncludeTest()
{
using (var context = new BikeRentalContext())
{
var rentals = context.Rentals
.Include(x => x.User)
//.Include(x => x.User.Parameters) // In case of chained references
.ToList();
foreach (var r in rentals)
{
WriteLine($"{r.DateFrom} - {r.DateTo}: {r.User.LastName}");
}
}
}
private static void UpdateBikeTest()
{
using (var context = new BikeRentalContext())
{
var bike = context.Bikes.AsNoTracking().First();
bike.Color = "yellow!";
//context.Entry(bike).State = EntityState.Added;
foreach (var e in context.ChangeTracker.Entries <Bike>())
{
WriteLine(e.Entity);
}
context.SaveChanges();
}
}
public void EagerLoadingTest()
{
using (var context = new BikeRentalContext())
{
var rentals = context.Rentals
.Include(r => r.User) // single
// .Include("User.Parameters") // deeper, not recommended
// .Include(r => r.User.Select) // deeper when list
// .Include(r => r.User.Parameters) // deeper only for objects
.ToList();
rentals.ForEach(r => Console.WriteLine($"{r.DateFrom} -> {r.User.FirstName} {r.User.LastName}")
);
}
}
private static void TransactionTest()
{
var badGuy = new Random();
using (var context = new BikeRentalContext())
using (var transaction = context.Database.BeginTransaction())
{
try
{
// First action
var user = new User
{
FirstName = "Jack",
LastName = "Doe"
};
context.Users.Add(user);
context.SaveChanges();
if (badGuy.Next(2) == 0)
{
throw new Exception("Imma bad guy!");
}
// Second action
var bikeToRent = context.Bikes.First();
var station = context.Stations.First();
var promoRental = new Rental
{
StationFrom = station,
Cost = 100,
DateFrom = DateTime.Now,
User = user,
Vehicle = bikeToRent
};
context.Rentals.Add(promoRental);
context.SaveChanges();
transaction.Commit();
}
catch (Exception ex)
{
transaction.Rollback();
WriteLine(ex);
}
}
}
private static void AddRental()
{
var userLukasz = new User
{
FirstName = "Lukasz",
LastName = $"K_{DateTime.Now.Hour}_{DateTime.Now.Minute}",
Discount = 60,
PhoneNumber = "123123123"
};
using (var dbContext = new BikeRentalContext())
{
try
{
dbContext.Users.Add(userLukasz);
dbContext.SaveChanges();
}
catch (Exception exception)
{
throw;
}
}
using (var dbContext = new BikeRentalContext())
{
var user = dbContext.Users.First(u => u.FirstName.Contains("Luk"));
var bike = dbContext.Vehicles.Find(1);
var station = dbContext.Stations.Find(1);
var rental = new Rental
{
Vehicle = bike,
User = user,
StationFrom = station,
DateFrom = DateTime.Now
};
try
{
dbContext.Rentals.Add(rental);
dbContext.SaveChanges();
}
catch (Exception exception)
{
throw;
}
}
}
