Data binding to list controls like ListBox and DropDownList is often used to present data to users in a ___________ format.
- Tabular
- Hierarchical
- Linear
- Sequential
The correct answer is "Linear." Data binding to list controls like ListBox and DropDownList usually presents data to users in a linear format, where each data item is displayed one after the other, typically in a single column. This format is suitable for displaying lists of options or items.
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.
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.
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.
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.
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.
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.
You have a LINQ query that performs multiple joins and retrieves a large dataset. What steps can you take to optimize the query's performance?
- Filtering Data
- Paging Results
- Proper Indexing
- Using IQueryable instead of IEnumerable
Proper Indexing: Indexing plays a crucial role in optimizing query performance, especially in scenarios involving multiple joins and large datasets. By ensuring that appropriate indexes are created on the columns used in joins and filtering conditions, you can significantly enhance query execution speed by allowing the database engine to quickly locate the required data. This optimization reduces the need for full table scans and improves overall query efficiency.
In LINQ to SQL, how can you retrieve a single record based on specific criteria?
- ExecuteQuery method
- ExecuteScalar method
- FirstOrDefault method
- Single method
When using LINQ to SQL, the FirstOrDefault method is used to retrieve a single record based on specific criteria. This method returns the first element of a sequence that satisfies a specified condition or a default value if no such element is found.
To optimize LINQ to Entities queries, consider using the ___________ method to specify what data to include in the result set.
- FirstOrDefault()
- Include()
- Skip()
- ToList()
The correct answer is Include(). The Include() method is used to specify related entities to include in the query result set. This can help optimize LINQ to Entities queries by fetching related data in a single round trip to the database, reducing the number of subsequent database calls for related data.
How can you configure the size of the connection pool in ADO.NET?
- By adjusting system registry settings, By modifying the database configuration, By increasing the number of available ports, By setting the "Max Pool Size" property in the connection string
- By adjusting system registry settings, By modifying the database configuration, By increasing the number of available ports, By setting the "Min Pool Size" property in the connection string
- By setting the "Max Pool Size" property in the connection string, By adjusting system registry settings, By modifying the database configuration, By increasing the number of available ports
- By setting the "Min Pool Size" property in the connection string, By adjusting system registry settings, By modifying the database configuration, By increasing the number of available ports
The size of the connection pool in ADO.NET can be configured by setting the "Max Pool Size" property in the connection string, specifying the maximum number of connections allowed in the pool.
In ADO.NET, the ___________ property of a command object specifies the maximum amount of time a command can run before being terminated.
- CommandTimeout
- CommandDuration
- TimeoutDuration
- ExecutionTimeLimit
The correct option is CommandTimeout. In ADO.NET, the CommandTimeout property of a command object allows you to specify the maximum amount of time (in seconds) that a command can execute before it is terminated. This property is useful in scenarios where you want to control the execution time of commands, preventing long-running queries from affecting application performance or causing timeouts.