public static void DeleteCustomer(string customerId)
{
using (var db = new NorthwindEntities())
{
var customerToRemove = db.Customers.Where(c => c.CustomerID == customerId).First();
db.Customers.Remove(customerToRemove);
db.SaveChanges();
}
Console.WriteLine("Customer deleted!");
}
//2.Create a DAO class with static methods which provide functionality for inserting, modifying and deleting customers.
public static void InsertCustomer(
string customerID,
string companyName,
string contactName = null,
string contactTitle = null,
string address = null,
string city = null,
string region = null,
string postalCode = null,
string country = null,
string phone = null,
string fax = null)
{
using (var db = new NorthwindEntities())
{
db.Customers.Add(new Customer()
{
CustomerID = customerID,
CompanyName = companyName,
ContactName = contactName,
ContactTitle = contactTitle,
Address = address,
City = city,
Region = region,
PostalCode = postalCode,
Country = country,
Phone = phone,
Fax = fax
});
db.SaveChanges();
}
Console.WriteLine("Inserted new customer!");
}
public static void UpdateCustomerPhone(
string customerId, string phone)
{
using (var db = new NorthwindEntities())
{
var customerToUpdate = db.Customers.Where(c => c.CustomerID == customerId).First();
customerToUpdate.Phone = phone;
db.SaveChanges();
}
Console.WriteLine("Customer phone changed!");
}
//7.Try to open two different data contexts and perform concurrent changes on the same records.
public static void MakeConcurrentChanges()
{
using (var db = new NorthwindEntities())
{
using (var anotherDB = new NorthwindEntities())
{
var category = db.Categories.Where(c => c.CategoryName == "Beverages").First();
category.Description = "First change";
var category2 = anotherDB.Categories.Where(c => c.CategoryName == "Beverages").First();
category2.Description = "Second Change";
db.SaveChanges();
anotherDB.SaveChanges();
}
}
}
