Scenario: You are tasked with optimizing the performance of an Entity Framework application. What strategies and techniques can you employ to improve database performance?

  • Compiled Queries
  • Eager Loading
  • Lazy Loading
  • Query Optimization
Query Optimization involves techniques such as indexing, avoiding unnecessary joins, and using appropriate filtering and sorting to improve database performance. By carefully crafting queries and utilizing database profiling tools, you can identify and address performance bottlenecks. Eager Loading and Lazy Loading are related to how Entity Framework retrieves related data but may not directly address database performance. Compiled Queries can improve performance by caching query execution plans, but they're only one aspect of optimizing database performance.

Which LINQ operator is used to perform set operations like union, intersection, and difference on sequences?

  • Concat
  • GroupBy
  • Join
  • Select
The Concat operator in LINQ is used to combine two sequences into a single sequence. It performs set operations such as union, intersection, and difference on the sequences. It takes two sequences as input and returns a new sequence containing all the elements from both input sequences, excluding duplicates. This operator is useful for combining data from multiple sources or performing set-based operations on collections.

Which SQL keyword is used to sort the result set in ascending order?

  • ASC
  • GROUP BY
  • ORDER BY
  • SORT
The ASC keyword is used in the ORDER BY clause to sort the result set in ascending order. It arranges the data in ascending order based on the specified column(s). Alternatively, you can use the keyword DESC to sort in descending order.

When handling concurrency conflicts in Entity Framework, you can use the ___________ property to detect changes made by other users.

  • ChangeTracker
  • ConcurrencyToken
  • Locking
  • Timestamp
In Entity Framework, the Timestamp property (also known as RowVersion) is often used to detect changes made by other users. This property is automatically updated by Entity Framework when an entity is modified.

The "Connection Reset" attribute in the connection string is used to ___________ the connection pool.

  • Empty
  • Flush
  • Refresh
  • Reset
The "Connection Reset" attribute in the connection string is used to reset the connection pool. When set to "True," it clears the pool of connections when a connection is retrieved from the pool.

What is an anonymous type in LINQ, and how is it used?

  • It is a predefined type in LINQ used for query expressions.
  • It is a type created dynamically at runtime to encapsulate data.
  • It is a type that can only be used within LINQ queries.
  • It is a type with no name used for declaring variables.
An anonymous type in LINQ is a type created dynamically at runtime to encapsulate data. It allows you to define a new type without explicitly declaring a class or struct. Anonymous types are typically used to store the results of query expressions or to project data into a new shape. They are convenient for one-time use cases where defining a formal type would be unnecessary overhead. However, they cannot be used outside of the method or scope where they are defined.

What is the purpose of the DataMember property in data binding?

  • Determines the type of data displayed in a grid view
  • Manages the data flow between multiple controls
  • Specifies the data source for the BindingSource component
  • Specifies the name of the data source column to bind to the UI control
The DataMember property in data binding is used to specify the name of the data source column to which a UI control is bound. It indicates which column from the data source should be displayed or manipulated in the UI control, facilitating proper data representation and interaction in WinForms applications.

When working with non-query commands, what does the ExecuteNonQuery method return as a result?

  • Error message
  • Result set
  • Rows affected
  • Scalar value
The ExecuteNonQuery method in ADO.NET returns the number of rows affected by the command, typically used with INSERT, UPDATE, DELETE queries. It does not return a result set or a scalar value. If there's an error, it may throw an exception.

In ADO.NET, what are the steps involved in updating data using a DataAdapter?

  • Fill the DataSet with data from the database
  • Initialize the DataAdapter with appropriate SQL commands
  • Modify the data in the DataSet
  • Update the database with changes from the DataSet
A DataAdapter in ADO.NET acts as a bridge between a database and a DataSet. To update data, the DataAdapter first fills the DataSet with data from the database, modifies the data within the DataSet, and then updates the database with the changes made in the DataSet.

When modifying data in datasets, what is the significance of the DataAdapter's Update method?

  • Connects to the database
  • Ensures changes are saved back to the database
  • Executes SQL commands
  • Retrieves data from the database
The DataAdapter's Update method is significant because it applies changes made to a DataSet back to the database. It synchronizes changes made in the DataSet with the corresponding rows in the database, ensuring that any modifications, deletions, or additions are reflected in the underlying data source.