private static void Main(string[] args)
{
//-- Poor-man DI - build our dependencies by hand for this demo
ISessionFactory sessionFactory = UserSessionFactory.CreateSessionFactory();
ISessionScopeFactory sessionScopeFactory = new SessionScopeFactory(sessionFactory);
IAmbientSessionLocator ambientSessionLocator = new AmbientSessionLocator();
IUserRepository userRepository = new UserRepository(ambientSessionLocator);
var userCreationService = new UserCreationService(sessionScopeFactory, userRepository);
var userQueryService = new UserQueryService(sessionScopeFactory, userRepository);
var userCreditScoreService = new UserCreditScoreService(sessionScopeFactory);
try
{
Console.WriteLine("This demo application will create a database named NH in the LocalDB SQL Server instance on localhost. Edit the connection string in UserSessionFactory if you'd like to create it somewhere else.");
Console.WriteLine("Press enter to start...");
Console.ReadLine();
//-- Demo of typical usage for read and writes
Console.WriteLine("Creating a user called Mary...");
var marySpec = new UserCreationSpec("Mary", "*****@*****.**");
userCreationService.CreateUser(marySpec);
Console.WriteLine("Done.\n");
Console.WriteLine("Trying to retrieve our newly created user from the data store...");
var mary = userQueryService.GetUser(marySpec.Id);
Console.WriteLine("OK. Persisted user: {0}", mary);
Console.WriteLine("Trying to retrieve our newly created user from the data store via a repository...");
var maryViaRepo = userQueryService.GetUserViaRepository(marySpec.Id);
Console.WriteLine("OK. Persisted user: {0}", maryViaRepo);
Console.WriteLine("Press enter to continue...");
Console.ReadLine();
//-- Demo of nested SessionScopes
Console.WriteLine("Creating 2 new users called John and Jeanne in an atomic transaction...");
var johnSpec = new UserCreationSpec("John", "*****@*****.**");
var jeanneSpec = new UserCreationSpec("Jeanne", "*****@*****.**");
userCreationService.CreateListOfUsers(johnSpec, jeanneSpec);
Console.WriteLine("Done.\n");
Console.WriteLine("Trying to retrieve our newly created users from the data store...");
var createdUsers = userQueryService.GetUsers(johnSpec.Id, jeanneSpec.Id);
Console.WriteLine("OK. Found {0} persisted users.", createdUsers.Count());
Console.WriteLine("Press enter to continue...");
Console.ReadLine();
//-- Demo of nested SessionScopes in the face of an exception.
// If any of the provided users failed to get persisted, none should get persisted.
Console.WriteLine("Creating 2 new users called Julie and Marc in an atomic transaction. Will make the persistence of the second user fail intentionally in order to test the atomicity of the transaction...");
var julieSpec = new UserCreationSpec("Julie", "*****@*****.**");
var marcSpec = new UserCreationSpec("Marc", "*****@*****.**");
try
{
userCreationService.CreateListOfUsersWithIntentionalFailure(julieSpec, marcSpec);
Console.WriteLine("Done.\n");
}
catch (Exception e)
{
Console.WriteLine(e.Message);
Console.WriteLine();
}
Console.WriteLine("Trying to retrieve our newly created users from the data store...");
var maybeCreatedUsers = userQueryService.GetUsers(julieSpec.Id, marcSpec.Id);
Console.WriteLine("Found {0} persisted users. If this number is 0, we're all good. If this number is not 0, we have a big problem.", maybeCreatedUsers.Count());
Console.WriteLine("Press enter to continue...");
Console.ReadLine();
//-- Demo of explicit database transaction isolation level.
Console.WriteLine("Trying to retrieve user John within a READ UNCOMMITTED database transaction...");
// You'll want to use SQL Profiler or Entity Framework Profiler to verify that the correct transaction isolation
// level is being used.
var userMaybeUncommitted = userQueryService.GetUserUncommitted(johnSpec.Id);
Console.WriteLine("OK. User found: {0}", userMaybeUncommitted);
Console.WriteLine("Press enter to continue...");
Console.ReadLine();
//-- Demonstration of SessionScope and parallel programming
Console.WriteLine("Calculating and storing the credit score of all users in the database in parallel...");
userCreditScoreService.UpdateCreditScoreForAllUsers();
Console.WriteLine("Done.");
}
catch (Exception e)
{
Console.WriteLine(e);
}
Console.WriteLine();
Console.WriteLine("The end.");
Console.WriteLine("Press enter to exit...");
Console.ReadLine();
}
