Linq To Sql Standard Database Operations Inserts

The first step to insert a record into a database is to create a DataContext. That is the first step for
every LINQ to SQL query.
Second, an entity object is instantiated from an entity class.
Third, that　entity object is inserted into the appropriate table collection. And fourth, the SubmitChanges method　is called on the DataContext.

1 Inserting a Record by Inserting an Entity Object into Table<T>

// 1. Create the DataContext.
Northwind db = new Northwind(@"Data Source=.\SQLEXPRESS;Initial Catalog=Northwind");
// 2. Instantiate an entity object.
Customer cust =
new Customer
{
CustomerID = "LAWN",
CompanyName = "Lawn Wranglers",
ContactName = "Mr. Abe Henry",
ContactTitle = "Owner",
Address = "1017 Maple Leaf Way",
City = "Ft. Worth",
Region = "TX",
PostalCode = "76104",
Country = "USA",
Phone = "(800) MOW-LAWN",
Fax = "(800) MOW-LAWO"
};
// 3. Add the entity object to the Customers table.
db.Customers.InsertOnSubmit(cust);
// 4. Call the SubmitChanges method.
db.SubmitChanges();

// 5. Query the record.
Customer customer = db.Customers.Where(c => c.CustomerID == "LAWN").First();
Console.WriteLine("{0} - {1}", customer.CompanyName, customer.ContactName);
// This part of the code merely resets the database so the example can be
// run more than once.
Console.WriteLine("Deleting the added customer LAWN.");
db.Customers.DeleteOnSubmit(cust);
db.SubmitChanges();

2. Inserting a Record into the Northwind Database by Adding It to EntitySet<T>

Northwind db = new Northwind(@"Data Source=.\SQLEXPRESS;Initial Catalog=Northwind");
Customer cust = (from c in db.Customers
where c.CustomerID == "LONEP"
select c).Single<Customer>();
// Used to query record back out.
DateTime now = DateTime.Now;

Order order = new Order
{
CustomerID = cust.CustomerID,
EmployeeID = 4,
OrderDate = now,
RequiredDate = DateTime.Now.AddDays(7),
ShipVia = 3,
Freight = new Decimal(24.66),
ShipName = cust.CompanyName,
ShipAddress = cust.Address,
ShipCity = cust.City,
ShipRegion = cust.Region,
ShipPostalCode = cust.PostalCode,
ShipCountry = cust.Country
};
cust.Orders.Add(order);
db.SubmitChanges();
IEnumerable<Order> orders =
db.Orders.Where(o => o.CustomerID == "LONEP" && o.OrderDate.Value == now);
foreach (Order o in orders)
{
Console.WriteLine("{0} {1}", o.OrderDate, o.ShipName);
}
// This part of the code merely resets the database so the example can be
// run more than once.
db.Orders.DeleteOnSubmit(order);
db.SubmitChanges();

3. Adding Attached Records

Northwind db = new Northwind(@"Data Source=.\SQLEXPRESS;Initial Catalog=Northwind");
Customer cust =
new Customer {
CustomerID = "LAWN",
CompanyName = "Lawn Wranglers",
ContactName = "Mr. Abe Henry",
ContactTitle = "Owner",
Address = "1017 Maple Leaf Way",
City = "Ft. Worth",
Region = "TX",
PostalCode = "76104",
Country = "USA",
Phone = "(800) MOW-LAWN",
Fax = "(800) MOW-LAWO",
Orders = {
new Order {
CustomerID = "LAWN",
EmployeeID = 4,
OrderDate = DateTime.Now,
RequiredDate = DateTime.Now.AddDays(7),
ShipVia = 3,
Freight = new Decimal(24.66),
ShipName = "Lawn Wranglers",
ShipAddress = "1017 Maple Leaf Way",
ShipCity = "Ft. Worth",
ShipRegion = "TX",
ShipPostalCode = "76104",
ShipCountry = "USA"
}
}
};

db.Customers.InsertOnSubmit(cust);
db.SubmitChanges();
Customer customer = db.Customers.Where(c => c.CustomerID == "LAWN").First();
Console.WriteLine("{0} - {1}", customer.CompanyName, customer.ContactName);
foreach (Order order in customer.Orders)
{
Console.WriteLine("{0} - {1}", order.CustomerID, order.OrderDate);
}
// This part of the code merely resets the database so the example can be
// run more than once.
db.Orders.DeleteOnSubmit(cust.Orders.First());
db.Customers.DeleteObSubmit(cust);
db.SubmitChanges();