public static Customer GetCustomerById(NorthwindEntities northwindEntities, string customerID)
{
var customer = northwindEntities.Customers
.FirstOrDefault(c => c.CustomerID == customerID);
return customer;
}
public static void ModifyCustomerCompanyName(string customerID, string newCompanyName)
{
using (var northwindEntities = new NorthwindEntities())
{
var customer = GetCustomerById(northwindEntities, customerID);
customer.CompanyName = newCompanyName;
northwindEntities.SaveChanges();
}
}
public static void DeleteCustomer(string customerID)
{
using (var northwindEntities = new NorthwindEntities())
{
Customer customer = GetCustomerById(northwindEntities, customerID);
northwindEntities.Customers.Remove(customer);
northwindEntities.SaveChanges();
}
}
public static void Main()
{
using (var db = new NorthwindEntities())
{
var categories = db.Categories.Count();
Console.WriteLine(categories);
}
}
public static void Main()
{
using (var northwindEntities = new NorthwindEntities())
{
// To solve this task you need to change in the app.config file the connection string to:
// initial catalog=NorthwindTwin
var result = northwindEntities.Database.CreateIfNotExists();
Console.WriteLine("Database NorthWindTwin is created: {0}", result ? "YES!" : "NO!");
}
}
public static string InsertNewCustomer(Customer customer)
{
if (customer == null)
{
throw new ArgumentNullException("You can not pass null as parameter");
}
using (var northwindEntities = new NorthwindEntities())
{
northwindEntities.Customers.Add(customer);
northwindEntities.SaveChanges();
return customer.CustomerID;
}
}
public static void Main()
{
using (var northwindEntities = new NorthwindEntities())
{
var employee = northwindEntities.Employees.First();
// The new model for the Employee is in 01.CreateDbContextForNorthwind
// in the file EmployeeExtended.cs
EntitySet<Territory> territories = employee.TerritoriesSet;
Console.WriteLine("All territories for employee {0} are:", employee.FirstName);
foreach (var territory in territories)
{
Console.WriteLine(territory.TerritoryDescription);
}
}
}
public static void Main()
{
const string nativeSqlQuery =
"SELECT c.ContactName AS [Customer], o.OrderDate [Order Year], o.ShipCountry " +
"FROM Customers c " +
"JOIN Orders o " +
"ON c.CustomerID = o.CustomerID " +
"WHERE YEAR(o.OrderDate) = 1997 AND o.ShipCountry = 'Canada'";
using (var db = new NorthwindEntities())
{
var customers = db.Database.SqlQuery<View>(nativeSqlQuery);
foreach (var customer in customers)
{
Console.WriteLine(customer);
}
}
}
public static void Main()
{
const string region = "SP";
var startDate = new DateTime(1995, 5, 10);
var endDate = new DateTime(1996, 12, 4);
using (var db = new NorthwindEntities())
{
var sales = db.Orders
.Where(o => o.ShipRegion == region &&
o.OrderDate >= startDate &&
o.OrderDate <= endDate)
.ToList();
foreach (var sale in sales)
{
Console.WriteLine("{0} | {1}", sale.ShipRegion, sale.OrderDate);
}
}
}
/// <summary>
/// Problem solved by only using only one connection or introducing transactions isolation levels
/// </summary>
public static void Main()
{
var firstConection = new NorthwindEntities();
var secondConection = new NorthwindEntities();
var customerFromFirstCon = firstConection.Customers.First();
var customerFromSecondCon = secondConection.Customers.First();
Console.WriteLine("Inital Name FisrtCon: {0} - SecondCon: {1}", customerFromFirstCon.CompanyName, customerFromSecondCon.CompanyName);
customerFromFirstCon.CompanyName = "Mercedes";
customerFromSecondCon.CompanyName = "Jaguar";
firstConection.SaveChanges();
secondConection.SaveChanges();
var result = new NorthwindEntities().Customers.First();
Console.WriteLine("Name After Change {0}", result.CompanyName);
}
public static void Main()
{
using (var db = new NorthwindEntities())
{
var customers = db.Customers
.Join(db.Orders,
(c => c.CustomerID),
(o => o.CustomerID),
(c, o) => new
{
CustomerName = c.ContactName,
OrderYear = o.OrderDate.Value.Year,
o.ShipCountry
})
.ToList()
.FindAll(c => c.OrderYear == 1997 && c.ShipCountry == "Canada")
.ToList();
foreach (var cust in customers)
{
Console.WriteLine(cust);
}
}
}