static void Listing18_4()
{
Console.WriteLine("{0} : Begin", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
TestDB db = new TestDB(@"Data Source=.\SQLEXPRESS;Initial Catalog=TestDB;Integrated Security=SSPI;");
db.Shapes.InsertOnSubmit(new Square {
Width = 4
});
db.Shapes.InsertOnSubmit(new Rectangle {
Width = 3, Length = 6
});
db.Shapes.InsertOnSubmit(new Rectangle {
Width = 11, Length = 5
});
db.Shapes.InsertOnSubmit(new Square {
Width = 6
});
db.Shapes.InsertOnSubmit(new Rectangle {
Width = 4, Length = 7
});
db.Shapes.InsertOnSubmit(new Square {
Width = 9
});
db.SubmitChanges();
Console.WriteLine("{0} : End", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
}
static void Listing18_5()
{
Console.WriteLine("{0} : Begin", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
TestDB db = new TestDB(@"Data Source=.\SQLEXPRESS;Initial Catalog=TestDB;Integrated Security=SSPI;");
// First I get all squares which will include rectangles.
IQueryable <Shape> squares = from s in db.Shapes
where s is Square
select s;
Console.WriteLine("The following squares exist.");
foreach (Shape s in squares)
{
Console.WriteLine("{0} : {1}", s.Id, s.ToString());
}
// Now I'll get just the rectangles.
IQueryable <Shape> rectangles = from r in db.Shapes
where r is Rectangle
select r;
Console.WriteLine("{0}The following rectangles exist.", System.Environment.NewLine);
foreach (Shape r in rectangles)
{
Console.WriteLine("{0} : {1}", r.Id, r.ToString());
}
Console.WriteLine("{0} : End", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
}
static void Listing18_3()
{
Console.WriteLine("{0} : Begin", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
TestDB db = new TestDB(@"Data Source=.\SQLEXPRESS;Initial Catalog=TestDB;Integrated Security=SSPI;");
db.CreateDatabase();
Console.WriteLine("{0} : End", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
}
static void Listing18_6()
{
Console.WriteLine("{0} : Begin", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
Northwind db = new Northwind(@"Data Source=.\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=SSPI;");
TestDB testDb = new TestDB(@"Data Source=.\SQLEXPRESS;Initial Catalog=TestDB;Integrated Security=SSPI;");
Customer cust = db.Customers.Where(c => c.CustomerID == "LONEP").SingleOrDefault();
cust.ContactName = "Barbara Penczek";
Rectangle rect = (Rectangle)testDb.Shapes.Where(s => s.Id == 3).SingleOrDefault();
rect.Width = 15;
try
{
using (System.Transactions.TransactionScope scope =
new System.Transactions.TransactionScope())
{
db.SubmitChanges();
testDb.SubmitChanges();
throw (new Exception("Just to rollback the transaction."));
// A warning will result because the next line cannot be reached.
scope.Complete();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
db.Refresh(System.Data.Linq.RefreshMode.OverwriteCurrentValues, cust);
Console.WriteLine("Contact Name = {0}", cust.ContactName);
testDb.Refresh(System.Data.Linq.RefreshMode.OverwriteCurrentValues, rect);
Console.WriteLine("Rectangle Width = {0}", rect.Width);
Console.WriteLine("{0} : End", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
}