private static void CreateSampleData(ISession session)
{
using (var transaction = session.BeginTransaction())
{
// create a couple of Stores each with some Products and Employees
var barginBasin = new Store { Name = "Bargin Basin" };
var superMart = new Store { Name = "SuperMart" };
var potatoes = new Product { Name = "Potatoes", Price = 3.60 };
var fish = new Product { Name = "Fish", Price = 4.49 };
var milk = new Product { Name = "Milk", Price = 0.79 };
var bread = new Product { Name = "Bread", Price = 1.29 };
var cheese = new Product { Name = "Cheese", Price = 2.10 };
var waffles = new Product { Name = "Waffles", Price = 2.41 };
var daisy = new Employee { FirstName = "Daisy", LastName = "Harrison" };
var jack = new Employee { FirstName = "Jack", LastName = "Torrance" };
var sue = new Employee { FirstName = "Sue", LastName = "Walkters" };
var bill = new Employee { FirstName = "Bill", LastName = "Taft" };
var joan = new Employee { FirstName = "Joan", LastName = "Pope" };
// add products to the stores, there's some crossover in the products in each
// store, because the store-product relationship is many-to-many
AddProductsToStore(barginBasin, potatoes, fish, milk, bread, cheese);
AddProductsToStore(superMart, bread, cheese, waffles);
// add employees to the stores, this relationship is a one-to-many, so one
// employee can only work at one store at a time
AddEmployeesToStore(barginBasin, daisy, jack, sue);
AddEmployeesToStore(superMart, bill, joan);
// save both stores, this saves everything else via cascading
session.SaveOrUpdate(barginBasin);
session.SaveOrUpdate(superMart);
transaction.Commit();
}
}
public virtual void AddEmployee(Employee employee)
{
employee.Store = this;
Staff.Add(employee);
}
static void Main(string[] args)
{
bool bCreateOrUpdateSchema = true;
bool bCreateSampleData = false || bCreateOrUpdateSchema;
var sessionFactory = CreateSessionFactory(bCreateOrUpdateSchema);
using (var session = sessionFactory.OpenSession())
{
if (bCreateSampleData)
{
CreateSampleData(session);
}
// get an entity by ID:
int employeeID = 1;
var emp = session.Get<Employee>(employeeID);
Console.WriteLine(String.Format("Employee ID {0} = {1}", employeeID, emp.FirstName));
int storeID = 1;
var store = session.Get<Store>(storeID);
Console.WriteLine(String.Format("Store ID {0} = {1}", storeID, store.Name));
// add a new employee:
var newEmp = new Employee{FirstName="Buzz",LastName="Lightyear"};
store.AddEmployee(newEmp);
session.Flush();
// query an entity using criteria query:
var crit = session.CreateCriteria<Employee>()
.Add(Expression.Eq("FirstName", "Buzz"));
IList<Employee> emps = crit.List<Employee>();
foreach (var empl in emps)
{
Console.WriteLine("Employee :" + empl.FirstName);
}
// modify an employee:
emp = emps.First();
emp.LastName = "Smith";
session.Flush();
// list all employees in a store
foreach (var empl in store.Staff)
{
Console.WriteLine(String.Format("Store {0} employee: {1} {2}",
store.Name,
empl.FirstName,
empl.LastName));
}
// delete all Buzzes
emps = session.CreateCriteria<Employee>()
.Add(Expression.Eq("FirstName", "Buzz"))
.List<Employee>();
foreach(var empl in emps)
{
Console.WriteLine(String.Format("Deleting employee {0} {1}", empl.FirstName, empl.LastName));
// you must remove the entity from associated collections, if you only do session.delete, you get an exception when doing session.flush()
store.Staff.Remove(empl);
session.Delete(empl);
}
session.Flush();
// re-list employees for one store:
foreach (var empl in store.Staff)
{
Console.WriteLine(String.Format("Store {0} employee: {1} {2}",
store.Name,
empl.FirstName,
empl.LastName));
}
// two in memory instances of the same entity, NHibernate is smart enough to get emp2 from the in memory version(not going back to the database)
// or at least the changes to emp1 are reflected in emp2:
var emp1 = session.Get<Employee>(1);
emp1.FirstName = "Sally";
var emp2 = session.Get<Employee>(1);
Console.WriteLine(String.Format("First employee instance: {0} {1}, second employee instance {2} {3}", emp1.FirstName, emp2.LastName, emp2.FirstName, emp2.LastName));
// its also smart enough to update other instances of the employee when we do this:
emp1.FirstName = "Daisy";
emp2.FirstName = "Sarah";
Console.WriteLine();
// both emp1 and emp2 now have a firstname of "Sarah"
Console.WriteLine(String.Format("First employee instance: {0} {1}, second employee instance {2} {3}", emp1.FirstName, emp2.LastName, emp2.FirstName, emp2.LastName));
session.Flush();
// are queries smart enough to use already loaded objects?
var empQuery = session.CreateCriteria<Employee>()
.Add(Expression.Eq("FirstName", "Sarah"))
.Add(Expression.Eq("LastName", "Harrison"));
emp1 = empQuery.List<Employee>().First();
emp1.FirstName = "Danielle";
var empQuery2 = session.CreateCriteria<Employee>()
.Add(Expression.Eq("FirstName", "Danielle"));
// this query returns nothing, because it goes back to the database:
Console.WriteLine("Query results for firstname=Danielle:");
foreach (var empl in empQuery2.List<Employee>())
{
Console.WriteLine(String.Format("{0} {1}", empl.FirstName, empl.LastName));
}
// we could probably re-use empQuery here, (but has that already been evaluated? if we call .List() again does it re-query?)
var empQuery3 = session.CreateCriteria<Employee>()
.Add(Expression.Eq("FirstName", "Sarah"));
// this query returns a value because the firstname is still sarah in the database
// but the value displayed is from the in-memory version, so the results of the query shows "danielle", not "sarah":
Console.WriteLine("Query results for firstname=Sarah:");
foreach (var empl in empQuery3.List<Employee>())
{
Console.WriteLine(String.Format("{0} {1}", empl.FirstName, empl.LastName));
}
Console.WriteLine("Press any key to exit");
Console.ReadKey();
}
}
