private static void AllRacers()
{
using (var data = new Formula1Entities())
{
ObjectSet <Racer> racers = data.Racers;
Console.WriteLine(racers.CommandText);
Console.WriteLine(racers.ToTraceString());
}
}
private static void UseObjectQuery()
{
using (var data = new Formula1Entities())
{
ObjectQuery <Racer> racers = data.CreateQuery <Racer>("[Formula1Entities].[Racers]");
Console.WriteLine(racers.CommandText);
Console.WriteLine(racers.ToTraceString());
}
}
private static void ObjectQueryFilter()
{
using (var data = new Formula1Entities())
{
string country = "Brazil";
ObjectQuery <Racer> racers = data.Racers.Where("it.Country = @Country", new ObjectParameter("Country", country));
Console.WriteLine(racers.CommandText);
Console.WriteLine(racers.ToTraceString());
}
}
private static void LinqQuery1()
{
using (var data = new Formula1Entities())
{
var racers = from r in data.Racers
where r.Wins > 40
orderby r.Wins descending
select r;
foreach (Racer r in racers)
{
Console.WriteLine("{0} {1}", r.Firstname, r.Lastname);
}
}
}
private static void TrackingDemo()
{
using (var data = new Formula1Entities())
{
data.ObjectStateManager.ObjectStateManagerChanged += ObjectStateManager_ObjectStateManagerChanged;
Racer niki1 = data.Racers.Where("it.Country='Austria' && it.Lastname='Lauda'").First();
Racer niki2 = data.Racers.Where("it.Country='Austria'").
OrderBy("it.Wins DESC").First();
if (Object.ReferenceEquals(niki1, niki2))
{
Console.WriteLine("the same object");
}
}
}
private static void EntitySQL()
{
using (var data = new Formula1Entities())
{
string country = "Brazil";
ObjectQuery <Racer> racers = data.CreateQuery <Racer>(
"SELECT VALUE it FROM ([Formula1Entities].[Racers]) AS it WHERE it.Country = @Country",
new ObjectParameter("Country", country));
foreach (var r in racers)
{
Console.WriteLine("{0} {1}", r.Firstname, r.Lastname);
}
}
}
private static void DetachDemo()
{
using (var data = new Formula1Entities())
{
data.ObjectStateManager.ObjectStateManagerChanged +=
ObjectStateManager_ObjectStateManagerChanged;
ObjectQuery <Racer> racers = data.Racers.Where("it.Lastname='Alonso'");
Racer fernando = racers.First();
EntityKey key = fernando.EntityKey;
data.Racers.Detach(fernando);
// Racer is now detached and can be changed independent of the object context
fernando.Starts++;
Racer originalObject = data.GetObjectByKey(key) as Racer;
data.Racers.ApplyCurrentValues(fernando);
}
}
private static void QueryBuilderMethods()
{
using (var data = new Formula1Entities())
{
string country = "USA";
ObjectQuery <Racer> racers = data.Racers.Where("it.Country = @Country",
new ObjectParameter("Country", country))
.OrderBy("it.Wins DESC, it.Starts DESC")
.Top("3");
foreach (var racer in racers)
{
Console.WriteLine("{0} {1}, wins: {2}, starts: {3}",
racer.Firstname, racer.Lastname, racer.Wins, racer.Starts);
}
}
}
private static void ChangeInformation()
{
using (var data = new Formula1Entities())
{
var jaime = new Racer
{
Firstname = "Jaime",
Lastname = "Alguersuari",
Country = "Spain",
Starts = 0
};
data.Racers.AddObject(jaime);
Racer fernando = data.Racers.Where("it.Lastname='Alonso'").First();
fernando.Starts++;
DisplayState(EntityState.Added.ToString(),
data.ObjectStateManager.GetObjectStateEntries(EntityState.Added));
DisplayState(EntityState.Modified.ToString(),
data.ObjectStateManager.GetObjectStateEntries(EntityState.Modified));
ObjectStateEntry stateOfFernando =
data.ObjectStateManager.GetObjectStateEntry(fernando.EntityKey);
Console.WriteLine("state of Fernando: {0}",
stateOfFernando.State.ToString());
foreach (string modifiedProp in stateOfFernando.GetModifiedProperties())
{
Console.WriteLine("modified: {0}", modifiedProp);
Console.WriteLine("original: {0}", stateOfFernando.OriginalValues[modifiedProp]);
Console.WriteLine("current: {0}", stateOfFernando.CurrentValues[modifiedProp]);
}
int changes = 0;
try
{
changes += data.SaveChanges();
}
catch (OptimisticConcurrencyException ex)
{
data.Refresh(RefreshMode.ClientWins, ex.StateEntries);
changes += data.SaveChanges();
}
Console.WriteLine("{0} entities changed", changes);
}
}
private static void LinqQuery2()
{
using (var data = new Formula1Entities())
{
var query = from r in data.Racers
from rr in r.RaceResults
where rr.Position <= 3 && rr.Position >= 1 && r.Country == "Switzerland"
group r by r.Id into g
let podium = g.Count()
orderby podium descending
select new
{
Racer = g.FirstOrDefault(),
Podiums = podium
};
foreach (var r in query)
{
Console.WriteLine("{0} {1} {2}", r.Racer.Firstname, r.Racer.Lastname, r.Podiums);
}
}
}
