When executing a LINQ to Entities query, the ___________ method is used to retrieve the results.

  • Execute
  • Fetch
  • Submit
  • ToList
When executing a LINQ to Entities query, the ToList method is used to retrieve the results. It materializes the query and returns the results as a List collection.

ADO.NET Datasets allow you to work with data in a ___________ manner.

  • Connected
  • Disconnected
  • Persistent
  • Semi-Connected
ADO.NET Datasets allow you to work with data in a disconnected manner. This means that after retrieving data from the database, the connection to the database is closed, and the data is held in memory until it is either updated in the dataset or discarded.

Scenario: You are developing an application that needs to query a list of customer objects stored in memory. Which LINQ technology would you choose for this task?

  • LINQ to Entities
  • LINQ to Objects
  • LINQ to SQL
  • LINQ to XML
LINQ to Objects is the appropriate choice for querying in-memory collections, such as lists of customer objects. It provides powerful querying capabilities against in-memory data structures.

To prevent SQL injection attacks, it is recommended to use ________ queries.

  • Dynamic
  • Embedded
  • Parameterized
  • Prepared
Parameterized queries are a recommended practice to prevent SQL injection attacks. By using parameters, the values provided by users are treated as data rather than executable code, thereby mitigating the risk of injection attacks.

Using a database-specific data provider, such as SqlClient, can result in ___________ performance compared to generic providers.

  • Improved
  • Deteriorated
  • Similar
  • Unpredictable
The correct option is Improved. Using a database-specific data provider, like SqlClient for SQL Server databases, often results in improved performance compared to generic providers such as OLEDB. This is because database-specific providers are optimized to leverage the features and capabilities of a particular database system, leading to better efficiency and resource utilization. Generic providers may introduce additional layers of abstraction and overhead, which can impact performance negatively.

To retrieve different data types from a data reader, you can use the _______ method.

  • GetField()
  • GetString()
  • GetType()
  • GetValue()
To retrieve different data types from a data reader, you can use the GetValue() method. This method returns the value of the specified column as an object, which you can then cast to the appropriate data type based on the data stored in the database.

In LINQ to SQL, what is the role of the DataContext class in query optimization?

  • Caching query results for faster access
  • Managing database connections and transactions
  • Optimizing the execution plan of generated SQL queries
  • Translating LINQ queries into SQL queries
In LINQ to SQL, the DataContext class plays a crucial role in query optimization by translating LINQ queries into SQL queries that are executed against the database. It ensures that LINQ queries are efficiently converted into optimized SQL queries, thereby enhancing performance.

Scenario: When you update data in a dataset, the changes should also be reflected in the underlying database. What ADO.NET component is responsible for syncing these changes with the database?

  • DataAdapter
  • SqlCommand
  • SqlConnection
  • SqlDataReader
The DataAdapter in ADO.NET serves as a bridge between a dataset and a database. It facilitates communication between the dataset and the database by executing SQL commands (such as INSERT, UPDATE, DELETE) and updating the database with changes made to the dataset. Hence, it ensures synchronization of data between the dataset and the underlying database.

What is the difference between the ExecuteReader() and ExecuteScalar() methods in ADO.NET when executing a SELECT statement?

  • ExecuteReader() and ExecuteScalar() both return a SqlDataReader object.
  • ExecuteReader() and ExecuteScalar() both return a single value from the result set.
  • ExecuteReader() returns a SqlDataReader object that allows forward-only access to the result set, while ExecuteScalar() returns a single value from the first column of the first row of the result set.
  • ExecuteReader() returns a single value from the first column of the first row of the result set, while ExecuteScalar() returns a SqlDataReader object that allows forward-only access to the result set.
ExecuteReader() and ExecuteScalar() are both methods in ADO.NET used to execute SELECT statements, but they differ in their return types and functionalities. ExecuteReader() returns a SqlDataReader object, which allows you to iterate through the result set row by row, while ExecuteScalar() returns a single value from the first column of the first row of the result set. This distinction is crucial when dealing with queries that return multiple rows or single values.

One-to-One relationships in Entity Framework can be mapped using the ___________ attribute.

  • [ForeignKey]
  • [InverseProperty]
  • [OneToOne]
  • [Table]
In Entity Framework, the [InverseProperty] attribute is utilized to define one-to-one relationships between entities, specifying the navigation property on the dependent entity.