You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create an application.
You are creating the data layer of the application. You write the following code segment.
(Line numbers are included for reference only.)
01 public static SqlDataReader GetDataReader(string sql)
02 {
03 SqlDataReader dr = null;
04 ...
05 return dr;
06 }
You need to ensure that the following requirements are met: The SqlDataReader returned by the GetDataReader method can be used to retreive rows from the database.
--
SQL connections opened within the GetDataReader method will close when the SqlDataReader is closed.
Which code segment should you insert at the line 04?

• A. SqlConnection cnn = new SqlConnection(strCnn); SqlCommand cmd = new SqlCommand(sql, cnn);
  cnn.Open();
  {
  try
  {
  dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
  }
  catch
  {
  cnn.Close();
  throw;
  }
  }
• B. SqlConnection cnn = new SqlConnection(strCnn); SqlCommand cmd = new SqlCommand(sql, cnn); cnn.Open(); { try { dr = cmd.ExecuteReader(); cnn.Close(); } catch {
  throw;
  }
  }
• C. SqlConnection cnn = new SqlConnection(strCnn); SqlCommand cmd = new SqlCommand(sql, cnn); cnn.Open(); { try { dr = cmd.ExecuteReader(); } finally {
  cnn.Close();
  }
  }
• D. using(SqlConnection cnn = new SqlConnection(strCnn)) { try { SqlCommand cmd = new SqlCommand(sql, cnn); cnn.Open(); dr = cmd.ExecuteReader(); } catch {
  throw;
  }
  }

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. The application uses the ADO.NET Entity
Framework to model entities.
The database includes objects based on the exhibit (click the Exhibit button).
The application includes the following code segment. (Line numbers are included for reference only.)
01 using(AdventureWorksEntities context = new AdventureWorksEntities())
02 {
03 ...
04 foreach (SalesOrderHeader order in customer.SalesOrderHeader)
05 {
06 Console.WriteLine(String.Format("Order: {0} ",
order.SalesOrderNumber));
07 foreach (SalesOrderDetail item in order.SalesOrderDetail)
08 {
09 Console.WriteLine(String.Format("Quantity: {0} ", item.Quantity));
10 Console.WriteLine(String.Format("Product: {0} ",
item.Product.Name));
11 }
12 }
13 }
You want to list all the orders for a specific customer. You need to ensure that the list contains following fields:
-Order number
-Quantity of products
-Product name
Which code segment should you insert in line 03?

• A. Contact customer = context.Contact.Where("it.ContactID = @customerId", new ObjectParameter("customerId", customerId)).First();
• B. Contact customer = context.Contact.Where("it.ContactID = @customerId", new ObjectParameter("@customerId", customerId)).First();
• C. Contact customer = (from contact in context.Contact.Include
  ("SalesOrderHeader")
  select contact).FirstOrDefault();
• D. Contact customer = (from contact in context.Contact.Include
  ("SalesOrderHeader.SalesOrderDetail")
  select contact).FirstOrDefault();

You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create an application.
You use the ADO.NET Entity Framework to model your entities.
You use Plain Old CLR Objects (POCO) entities along with snapshot-based change tracking. The code
accesses the POCO entities directly.
You need to ensure that the state manager synchronizes when changes are made to the object graph.
Which ObjectContext method should you call?

• A. DetectChanges
• B. SaveChanges
• C. Refresh
• D. ApplyPropertyChanges

You use Microsoft .NET Framework 4.0 and the Entity Framework to develop an application.
You create an Entity Data Model that has an entity named Customer. You set the optimistic concurrency
option for Customer.
You load and modify an instance of Customer named loadedCustomer, which is attached to an
ObjectContext named context.
You need to ensure that if a concurrency conflict occurs during a save, the application will load up-to-date
values from
the database while preserving local changes. Which code segment should you use?

• A. try {
  context.SaveChanges();
  }
  catch(EntitySqlException ex)
  {
  context.Refresh(RefreshMode.StoreWins, loadedCustomer);
  }
• B. try {
  context.SaveChanges();
  }
  catch(OptimisticConcurrencyException ex)
  {
  context.Refresh(RefreshMode.StoreWins, loadedCustomer);
  }
• C. try {
  context.SaveChanges();
  }
  catch(OptimisticConcurrencyException ex)
  {
  context.Refresh(RefreshMode.ClientWins, loadedCustomer);
  }
• D. try {
  context.SaveChanges();
  }
  catch(EntitySqlException ex)
  {
  context.Refresh(RefreshMode.ClientWins, loadedCustomer);
  }

You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create an application.
You use the ADO.NET Entity Data Model (EDM) to define a Customer entity.
You need to add a new Customer to the data store without setting all the customer's properties. What
should you do?

• A. Call the CreateObject method of the Customer object.
• B. Override the SaveChanges method for the Customer object.
• C. Override the Create method for the Customer object.
• D. Call the Create method of the Customer object.