private static void FunWithLINQQueries()
{
using (AutoLotEntities context = new AutoLotEntities())
{
// Get all data from the Inventory table.
// Could also write:
// var allData = (from item in context.Cars select item).ToArray();
var allData = context.Cars.ToArray();
// Get a projection of new data.
var colorsMakes = from item in allData select new { item.Color, item.Make };
foreach (var item in colorsMakes)
{
Console.WriteLine(item);
}
// Get only items where CarID < 1000.
var idsLessThan1000 = from item in allData
where item.CarID < 1000
select item;
foreach (var item in idsLessThan1000)
{
Console.WriteLine(item);
}
}
}
private static void PrintAllInventory()
{
// Select all items from the Inventory table of AutoLot,
// and print out the data using our custom ToString()
// of the Car entity class.
using (AutoLotEntities context = new AutoLotEntities())
{
foreach (Car c in context.Cars)
{
Console.WriteLine(c);
}
}
}
private static void RemoveRecord()
{
// Find a car to delete by primary key.
using (AutoLotEntities context = new AutoLotEntities())
{
// See if we have it?
var carToDelete =
(from c in context.Cars where c.CarID == 2222 select c).FirstOrDefault();
if (carToDelete != null)
{
context.Cars.Remove(carToDelete);
context.SaveChanges();
}
}
}
private static void FunWithEntitySQL()
{
using (AutoLotEntities context = new AutoLotEntities())
{
// Build a string containing Entity SQL syntax.
string query = "SELECT VALUE car FROM AutoLotEntities.Cars " +
"AS car WHERE car.Color='black'";
var objectContext = (context as IObjectContextAdapter).ObjectContext;
// Now build an ObjectQuery<T> based on the string.
var blackCars = objectContext.CreateQuery <Car>(query);
foreach (var item in blackCars)
{
Console.WriteLine(item);
}
}
}
private static void UpdateRecord()
{
// Find a car to delete by primary key.
using (AutoLotEntities context = new AutoLotEntities())
{
// Define a key for the entity we are looking for.
EntityKey key = new EntityKey("AutoLotEntities.Cars", "CarID", 2222);
// Grab the car, change it, save!
Car carToUpdate =
(from c in context.Cars where c.CarID == 2222 select c).FirstOrDefault();
if (carToUpdate != null)
{
carToUpdate.Color = "Blue";
context.SaveChanges();
}
}
}
private static void AddNewRecord()
{
// Add record to the Inventory table of the AutoLot
// database.
using (AutoLotEntities context = new AutoLotEntities())
{
try
{
// Hard-code data for a new record, for testing.
context.Cars.Add(new Car()
{
CarID = 2222,
Make = "Yugo",
Color = "Brown"
});
context.SaveChanges();
}
catch (Exception ex)
{
Console.WriteLine(ex.InnerException.Message);
}
}
}
