Microsoft TS: Accessing Data with Microsoft .NET Framework 4 Sample Questions:

1. You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to develop an application that
uses the Entity Framework.
The application has an entity model that includes SalesTerritory and SalesPerson entities as shown in the
following diagram.

You need to calculate the total bonus for all sales people in each sales territory. Which code segment should you use?

A) model.SalesPersons .GroupBy(person => person.SalesTerritory) .SelectMany(group => group.Key.SalesPersons) .Sum(person => person.Bonus);
B) model.SalesTerritories .GroupBy(territory => territory.SalesPersons) .SelectMany(group => group.Key) .Sum(person => person.Bonus);
C) from person in model.SalesPersons group person by person.SalesTerritory into territoryByPerson select new {
SalesTerritory = territoryByPerson.Key,
TotalBonus = territoryByPerson.Sum(person => person.Bonus)
};
D) from territory in model.SalesTerritories group territory by territory.SalesPerson into personByTerritories select new {
SalesTerritory = personByTerritories.Key,
TotalBonus = personByTerritories.Key.Sum(person => person.Bonus)
};

2. You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to create an application.
You create a Database Access Layer (DAL) that is database-independent. The DAL includes the following
code segment.
(Line numbers are included for reference only.)
01 static void ExecuteDbCommand(DbConnection connection)
02 {
03 if (connection != null){
04 using (connection){
05 try{
06 connection.Open();
07 DbCommand command = connection.CreateCommand();
08 command.CommandText = "INSERT INTO Categories (CategoryName)
VALUES ('Low Carb')";
09 command.ExecuteNonQuery();
10 }
11 ...
12 catch (Exception ex){
13 Trace.WriteLine("Exception.Message: " + ex.Message);
14 }
15 }
16 }
17 }
You need to log information about any error that occurs during data access.
You also need to log the data provider that accesses the database. Which code segment should you insert
at line 11?

A) catch (DbException ex){ Trace.WriteLine("ExceptionType: " + ex.Source);
Trace.WriteLine("Message: " + ex.Message);
}
B) catch (OleDbException ex){ Trace.WriteLine("ExceptionType: " + ex.Source);
Trace.WriteLine("Message: " + ex.Message);
}
C) catch (DbException ex){ Trace.WriteLine("ExceptionType: " + ex.InnerException.Source);
Trace.WriteLine("Message: " + ex.InnerException.Message);
}
D) catch (OleDbException ex){ Trace.WriteLine("ExceptionType: " + ex.InnerException.Source);
Trace.WriteLine("Message: " + ex.InnerException.Message);
}

3. 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 use Entity SQL to retrieve data from the
database.
You need to find out whether a collection is empty. Which entity set operator should you use?

A) ANYELEMENT
B) EXCEPT
C) IN
D) EXISTS

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

5. You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4.0 to develop an application. You use the ADO.NET Entity Framework Designer to model entities as shown in the following diagram.

You create an ObjectContext instance named objectContext1 and use it to create a SalesPerson instance
named person1.
You create an ObjectContext instance named objectContext2 and use it to create a SalesTerritory instance
named territory1.
You need to create and persist a relationship between person1 and terrotory1. What should you do?

A) Detach person1 from objectContext1. Attach person1 to objectContext2. Set the SalesTerritory property of person1 to territory1. Call SaveChanges on objectContext2.
B) Detach person1 from objectContext1. Detach territory1 from objectContext2. Set the SalesTerritory property of person1 to territory1. Call Refresh on both objectContext1 and objectContext2.
C) Attach person1 to objectContext2. Attach territory1 to objectContext1. Set the SalesTerritory property of person1 to territory1. Call SaveChanges on both objectContext1 and objectContext2.
D) Attach person1 to objectContext2. Detach territory1 from objectContext2. Set the SalesTerritory property of person1 to territory1. Call Refresh on objectContext1.

Solutions: