The IsolationLevel enumeration in ADO.NET provides options such as ReadCommitted and ___________.
- Serializable
- ReadUncommitted
- RepeatableRead
- Snapshot
The IsolationLevel enumeration in ADO.NET provides options such as ReadCommitted, which ensures that a transaction reads only committed data. RepeatableRead ensures that a transaction can reread data it has previously read.
Which ADO.NET class is commonly used to execute non-query commands?
- SqlCommand
- SqlConnection
- SqlDataAdapter
- SqlDataReader
The SqlCommand class in ADO.NET is commonly used to execute non-query commands such as INSERT, UPDATE, and DELETE. It represents a SQL statement or stored procedure to execute against a SQL Server database.
What is two-way data binding, and how does it differ from one-way data binding?
- It allows data to flow only from the UI control to the data source.
- It allows data to flow only from the data source to the UI control.
- It enables synchronization of data between the UI control and data source.
- It involves no synchronization between the UI control and data source.
Two-way data binding facilitates bidirectional communication between the UI control and the data source. Changes made in the UI control are reflected in the data source, and vice versa. In contrast, one-way data binding allows data to flow in only one direction, either from the data source to the UI control or vice versa, but not both simultaneously.
In ADO.NET, how can you establish relationships between multiple DataTables within a single dataset?
- Using DataConnections
- Using DataMappings
- Using DataMappings and DataConnections
- Using DataRelations
In ADO.NET, relationships between multiple DataTables within a single dataset are established using DataRelations. DataRelations represent relationships between DataTables and are defined by specifying parent and child columns. These relationships allow for navigation between related data tables and are essential for maintaining data integrity in a dataset.
ADO.NET provides the SqlConnection ___________ method to explicitly close a database connection.
- Disconnect()
- Close()
- Dispose()
- Release()
In ADO.NET, the SqlConnection class offers the Close() method to explicitly close a database connection. This method ensures that the connection to the database is properly terminated, releasing associated resources. Although there are methods like Dispose() and Disconnect(), they don't directly serve the purpose of closing the connection in the SqlConnection class. Therefore, "Close()" is the correct option.
The use of ___________ can help in caching query results and improving query performance.
- AsNoTracking()
- FirstOrDefault()
- Include()
- ToList()
The correct answer is AsNoTracking(). By using AsNoTracking(), Entity Framework Core does not keep track of the entities retrieved from the database, which can help in caching query results and improving query performance, especially in read-only scenarios where entities are not modified.
What is the primary purpose of the DbContext class in Entity Framework?
- To define the mapping between entity classes and database tables
- To define the structure of the database and manage migrations
- To handle database transactions and concurrency
- To represent a session with the database and provide APIs for querying and saving data
The DbContext class in Entity Framework serves as the primary entry point for interacting with the database. It represents a session with the database and provides APIs for querying and saving data. DbContext also manages the connection to the database, tracks changes to entities, and facilitates change tracking, which is essential for implementing features like lazy loading and change tracking.
In ADO.NET, what is the primary role of the DataAdapter?
- Executes SQL commands and returns a result set
- Provides a forward-only, read-only cursor for accessing data
- Represents a connected architecture for interacting with a database
- Retrieves data from the database and populates a DataSet
The primary role of the DataAdapter in ADO.NET is to retrieve data from the database and populate a DataSet. It acts as a bridge between the database and the DataSet, facilitating communication and data transfer.
The Entity Framework enables developers to work with data using a ___________-first approach.
- Code
- Data
- Database
- Model
The Entity Framework enables developers to work with data using a code-first approach. In this approach, you define your model classes first, and then the database schema is generated based on those classes.
The Entity Framework ___________ feature allows you to specify how entity classes are mapped to database tables.
- Code-First
- Code-Last
- Code-Only
- Code-Middle
The correct option is "Code-First." Code-First is a feature of Entity Framework that allows developers to define the domain model classes first, and then generate the database schema based on those classes. This approach provides flexibility and control over the database design while working primarily with object-oriented code.