Microsoft TS: Accessing Data with Microsoft .NET Framework 4 認定 70-516 試験問題:

1. You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create an application. The application connects to a Microsoft SQL Server database. You create the classes shown in the following exhibit:

You add the following code segment to the application. (Line numbers are included for reference only.)
01 public void QueryPlayers (List <League> leagues) {
02 ...
03 }
You create a LINQ query to retrieve a collection of Player objects.
You need to ensure that the collection includes all the players from each team and every league. Which
code segment should you insert at line 02?

A) var query = leagues.SelectMany(l => l.Teams.SelectMany(t => t.Players));
B) var query = leagues.Select(l => l.Teams.SelectMany(t => t.Players));
C) var query = leagues.SelectMany(l => l.Teams.Select(t => t.Players));
D) var query = leagues.Select(l => l.Teams.Select(t => t.Players));

2. A performance issue exists in the application. The following code segment is causing a performance bottleneck:
var colors = context.Parts.GetColors();
You need to improve application performance by reducing the number of database calls. Which code segment should you use?

A) var colors = context.Parts.OfType<Product>().Include ("Product.Color").GetColors();
B) var colors = context.Parts.OfType<Product>().Include("Color").GetColors();
C) var colors = context.Parts.OfType<Product>().Include ("Parts.Color").GetColors();
D) var colors = context.Parts.OfType<Product>().Include("Colors").GetColors();

3. You use Microsoft Visual Studio 2010 and Microsoft Entity Framework 4.0 to create an application.
The application connects to a Microsoft SQL Server database. You use the ADO.NET LINQ to SQL model
to retrieve data from the database.
The applications contains the Category and Product entities as shown in the following exhibit:

You need to ensure that LINO to SQL executes only a single SQL statement against the database. You also need to ensure that the query returns the list of categories and the list of products.
Which code segment should you use?
Exhibit:

A) using (NorthwindDataContext dc = new NorthwindDataContext()) { dc.DeferredLoadingEnabled = false;
var categories = from c in dc.Categories
select c;
foreach (var category in categories) { Console.WriteLine("{0} has {1} products", category.CategoryName, category.Products.Count); } }
B) using (NorthwindDataContext dc = new NorthwindDataContext()) { dc.DeferredLoadingEnabled = false;
DataLoadOptions dlOptions = new DataLoadOptions();
dlOptions.AssociateWith<Category>(c => c.Products);
dc.LoadOptions = dlOptions;
var categories = from c in dc.Categories
select c;
foreach (var category in categories) { Console.WriteLine("{0} has {1} products", category.CategoryName, category.Products.Count); } }
C) using (NorthwindDataContext dc = new NorthwindDataContext()) { dc.ObjectTrackingEnabled = false;
var categories = from c in dc.Categories
select c;
foreach (var category in categories) { Console.WriteLine("{0} has {1} products", category.CategoryName, category.Products.Count); } }
D) using (NorthwindDataContext dc = new NorthwindDataContext()) { dc.DeferredLoadingEnabled = false;
DataLoadOptions dlOptions = new DataLoadOptions();
dlOptions.LoadWith<Category>(c => c.Products);
dc.LoadOptions = dlOptions;
var categories = from c in dc.Categories select c;
foreach (var category in categories) { Console.WriteLine("{0} has {1} products", category.CategoryName, category.Products.Count); } }

4. You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create an application.
The application uses the ADO.NET Entity Framework to model entities.
The application allows users to make changes to entities while disconnected from the central data store.
You need to ensure that when the user connects to the central data store and retrieves new data, the application meets the following requirements:
-Changes made to the local data store in disconnected mode are preserved.
-Entities that have already been loaded into the local data store, but have not been modified by the user,
are updated with the latest data. What should you do?

A) Call the query's Execute method by using the MergeOptions.OverwriteChanges option.
B) Call the Refresh method of ObjectContext by using the RefreshMode.StoreWins option.
C) Call the query's Execute method by using the MergeOptions.AppendOnly option.
D) Call the Refresh method of ObjectContext by using the RefreshMode.ClientWins option.

5. You need to ensure that an exception is thrown when color names are set to less than two characters. What should you do?

A) Add the following attribute to the Name property of the Color class in the entity designer file:
[StringLength(256, MinimumLength = 2)]
B) Add the following method to the Color partial class in Model\Color.cs:
protected overrride void OnPropertyChanged(string property)
{
if (property == "Name" && this.Name.Length < 2)
throw new ArgumentOutOfRangeException("Name must be at least two
characters");
}
C) Add the following code segment to the ContosoEntities partial class in Model\ContosoEntities.cs:
public override in SaveChanges(System.Data.Objects.SaveOptions options)
{
var changes = this.ObjectStateManager.GetObjectSateEntries
(System.Data.EntityState.Added);
foreach (var change in changes)
{
if (change.Entity is Color) if (((Color)change.Entity.Name.Length < 2) throw new ArgumentException ("Name too short");
}
return base.SaveChanges(options);
}
D) Add the following method to the Color partial class in Model\Color.cs:
protected overrride void OnPropertyChanging(string property)
{
if (property == "Name" && this.Name.Length < 2)
throw new ArgumentOutOfRangeException("Name must be at least two
characters");
}

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