When dealing with hierarchical data, what is a typical use case for DataRelations?

  • Filtering data within a dataset
  • Navigating and manipulating related data across multiple tables
  • Retrieving data from a single table
  • Sorting data within a dataset
DataRelations in ADO.NET are commonly used to navigate and manipulate related data across multiple tables within a hierarchical dataset, enabling operations such as fetching child records for a given parent record.

The DataRelation class is used to define relationships between ___________.

  • DataColumns
  • DataRows
  • DataSet objects
  • DataTables
The DataRelation class in ADO.NET is used to establish relationships between DataTable objects within a DataSet. It defines a relationship between two DataTables based on DataColumn objects. This enables you to navigate and query related data across multiple tables in the DataSet using the defined relationships.

What is deferred execution in the context of LINQ to DataSet?

  • It allows modifying the source data directly within the LINQ query
  • It involves executing LINQ queries immediately upon creation
  • It is a mechanism to prevent execution of certain LINQ queries
  • It refers to the delayed execution of LINQ queries until the query result is actually needed
Deferred execution in LINQ to DataSet refers to the delayed execution of LINQ queries until the query result is actually needed. Instead of executing the query immediately upon creation, LINQ to DataSet postpones the execution until the query result is requested or iterated over. This approach offers several benefits, such as improved performance by minimizing database round trips and enabling the construction of more flexible and efficient query expressions. Understanding deferred execution is crucial for optimizing LINQ to DataSet queries and enhancing overall application performance.

How does the .NET Framework support custom data providers in ADO.NET?

  • By allowing developers to implement specific classes
  • By providing built-in support for all databases
  • By relying on third-party libraries
  • Through the IDbConnection interface
The .NET Framework supports custom data providers in ADO.NET by allowing developers to implement specific classes that adhere to the ADO.NET provider model. This model defines a set of interfaces, such as IDbConnection and IDbCommand, that custom providers can implement to interact with different databases. By implementing these interfaces, developers can create custom data providers that integrate seamlessly with the ADO.NET architecture and leverage its features.

ADO.NET allows you to work with which types of data sources?

  • Both relational databases and XML data sources
  • None of the above
  • Relational databases
  • XML data sources
ADO.NET in .NET allows developers to work with both relational databases and XML data sources. This flexibility enables seamless integration of different types of data into applications, providing versatility in data handling and manipulation.

Understanding the characteristics and features of each data provider is crucial for ___________ database connectivity in ADO.NET.

  • Effective
  • Efficient
  • Optimal
  • Successful
Understanding the characteristics and features of each data provider is crucial for successful database connectivity in ADO.NET. Different providers have unique features and capabilities that impact performance and functionality in accessing databases.

How can you handle transaction rollbacks and error handling in ADO.NET?

  • Ignoring errors and allowing transactions to commit regardless.
  • Implementing try-catch blocks to catch exceptions and rolling back transactions in the catch block.
  • Manually reverting changes made during a transaction in case of errors.
  • Using nested transactions to ensure proper rollback handling.
Transaction rollbacks and error handling in ADO.NET involve implementing proper exception handling mechanisms, typically using try-catch blocks to catch exceptions that may occur during transaction execution. Upon catching an exception, the transaction can be rolled back to maintain data integrity. Ignoring errors or allowing transactions to commit despite errors can lead to data inconsistencies.

Scenario: You need to insert a new customer record into a SQL Server database using LINQ to SQL. Which LINQ to SQL method or operation would you use for this task?

  • Add
  • Attach
  • InsertOnSubmit
  • Update
InsertOnSubmit method is used to insert a new record into a LINQ to SQL data context. It queues the object to be inserted upon calling the SubmitChanges method. This method is specifically designed for adding new records. The Add method is not part of LINQ to SQL; it's typically used with Entity Framework. Update is used to modify existing records, and Attach is used to attach existing objects to a data context, not for inserting new records.

When using connection pooling, the database connection remains open in a ___________ state.

  • Active
  • Closed
  • Idle
  • Reserved
Connection pooling is a technique used to manage database connections efficiently. When a connection is not actively being used, it enters an idle state, ready to be reused. This helps in reducing the overhead of opening and closing connections frequently.

Scenario: You are developing a Windows Forms application and need to display a list of customer records from a database. Which ADO.NET control or method of data binding would you use?

  • DataGridView
  • DataReader
  • DataAdapter
  • ListBox
The correct option is DataGridView. DataGridView is a powerful control in ADO.NET for displaying and editing tabular data. It provides a customizable and efficient way to bind data from a database, making it ideal for displaying customer records in a Windows Forms application. DataReader is typically used for read-only, forward-only access to data, DataAdapter is used for filling datasets, and ListBox is more suitable for displaying simple lists of items.

In Entity Framework Code-First, the DbContext class acts as a bridge between the application and the _________.

  • Data Access Layer
  • Data Model
  • Database
  • User Interface
In Entity Framework Code-First, the DbContext class serves as a bridge between the application and the data model. It represents a session with the database and can be used to query and save instances of your entities.

You need to retrieve data from multiple related tables in a database using a single SQL query. Which SQL clause will be crucial in this situation?

  • JOIN
  • WHERE
  • GROUP BY
  • HAVING
The correct option is JOIN. The JOIN clause is crucial for retrieving data from multiple related tables in a single SQL query. It allows you to combine rows from two or more tables based on a related column between them. Using JOINs helps in avoiding multiple queries and improves query performance.