You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create a Windows
Communication
Foundation (WCF) Data Services service. You deploy the data service to the following URL: http://
contoso.com/Northwind.svc.
You add the following code segment. (Line numbers are included for reference only.)
01 var uri = new Uri(@"http://contoso.com/Northwind.svc/");
02 var ctx = new NorthwindEntities(uri);
03 var categories = from c in ctx.Categories select c;
04 foreach (var category in categories) {
05 PrintCategory(category);
06 ...
07 foreach (var product in category.Products) {
08 ...
09 PrintProduct(product);
10 }
11 }
You need to ensure that the Product data for each Category object is lazy-loaded. What should you do?

• A. Add the following code segment at line 06:
  ctx.LoadProperty(category, "Products");
• B. Add the following code segment at line 08:
  ctx.LoadProperty(product, "*");
• C. Add the following code segment at line 06:
  var strPrdUri = string.Format("Categories({0})?$expand=Products",
  category.CategoryID);
  var productUri = new Uri(strPrdUri, UriKind.Relative);
  ctx.Execute<Product>(productUri);
• D. Add the following code segment at line 08:
  var strprdUri= string.format("Products?$filter=CategoryID eq {0}",
  category.CategoryID);
  var prodcutUri = new Uri(strPrd, UriKind.Relative);
  ctx.Execute<Product>(productUri);

You use Microsoft .NET Framework 4.0 to develop an application that connects to a local Microsoft SQL
Server 2008 database.
The application can access a high-resolution timer. You need to display the elapsed time, in sub-
milliseconds (<1 millisecond),
that a database query takes to execute. Which code segment should you use?

• A. Stopwatch sw = Stopwatch.StartNew(); command.ExecuteNonQuery() ; sw.Stop() ; Console.WriteLine("Time Elapsed: {0:N} ms", sw.Elapsed.TotalMilliseconds);
• B. DateTime Start = DateTime.UtcNow; command.ExecuteNonQuery(); TimeSpan Elapsed = DateTime.UtcNow - Start; Console.WriteLine("Time Elapsed: {0:N} ms", Elapsed.Milliseconds);
• C. Stopwatch sw = new Stopwatch(); sw.Start() ; command.ExecuteNonQuery(); sw.Stop(); Console.WriteLine("Time Elapsed: {0:N} ms", sw.Elapsed.Milliseconds);
• D. int Start = Environment.TickCount; command.ExecuteNonQuery(); int Elapsed = (Environment.TickCount) - Start; Console.WriteLine("Time Elapsed: {0:N} ms", Elapsed);

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. You create an entity as shown in
the following code fragment.
<EntityType Name="ProductCategory">
<Key>
<PropertyRef Name="ProductCategoryID" />
</Key>
<Property Name="ProductCategoryID" Type="int" Nullable="false" StoreGeneraedPattern="Identity" />
<Property Name="ParentProductCategoryID" Type="int" />
<Property Name="Name" Type="nvarchar" Nullable="false" MaxLength="50" />
...
</EntityType>
You need to provide two entity-tracking fields:
-rowguid that is automatically generated when the entity is created
-ModifiedDate that is automatically set whenever the entity is updated. Which code fragment should you add to the .edmx file?

• A. <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" StoreGeneratedPattern="Computed"/> <Property Name="ModifiedDate" Type="timestamp" Nullable="false" StoreGeneratedPattern="Identity"/>
• B. <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" StoreGeneratedPattern="Identity"/> <Property Name="ModifiedDate" Type="timestamp" Nullable="false" StoreGeneratedPattern="Computed"/>
• C. <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" StoreGeneratedPattern="Computed"/> <Property Name="ModifiedDate" Type="timestamp" Nullable="false" StoreGeneratedPattern="Computed"/>
• D. <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" StoreGeneratedPattern="Identity"/> <Property Name="ModifiedDate" Type="timestamp" Nullable="false" StoreGeneratedPattern="Identity"/>

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