Data readers are typically used for which type of database operations?
- Creating new database objects
- Deleting database objects
- Reading data from the database
- Updating data in the database
Data readers in ADO.NET are primarily used for reading data from the database. They provide a lightweight and efficient way to sequentially retrieve query results, allowing applications to process large datasets without the overhead of loading the entire result set into memory. While data readers excel at data retrieval operations, they are not designed for updating or modifying data in the database, as they provide read-only access to query results.
The where clause in LINQ is used for ___________ elements based on specified criteria.
- Aggregating
- Filtering
- Grouping
- Sorting
The where clause in LINQ is primarily used for filtering elements based on specified criteria, allowing developers to select only those that meet certain conditions.
How can you create a filtered view of data from a DataSet using DataViews?
- Use the DataView.Filter method to apply a filter expression to the DataView.
- Use the DataView.RowFilter property to specify filter criteria based on column values.
- Use the DataView.RowStateFilter property to filter rows based on their state (e.g., Added, Modified, Deleted).
- Use the DataView.Select method to select specific rows from the DataView.
To create a filtered view of data from a DataSet using DataViews, you can use the RowFilter property of the DataView. This property allows you to specify filter criteria based on column values, thereby creating a filtered view of the data according to your requirements.
One of the advantages of data binding is that it helps in keeping the UI and ___________ in sync.
- Business logic
- Data manipulation
- Database
- Presentation
One of the advantages of data binding is that it helps in keeping the UI and presentation in sync with the underlying data, ensuring consistency between what is displayed and what is stored.
Scenario: In a LINQ to DataSet query, you encounter the concept of deferred execution. Explain what deferred execution means and provide an example of when it might be advantageous.
- Execution of query happens after modifying the underlying data.
- Execution of query happens in parallel with other operations.
- Execution of query is immediate and results are generated as soon as the query is executed.
- Execution of query is postponed until the results are actually requested or iterated over.
Deferred execution means that the execution of the LINQ query is delayed until the results are actually needed. This postponement allows for better performance optimization, especially when dealing with large datasets, as it avoids unnecessary computations until the results are required. For example, when dealing with complex queries or when the query result is not immediately needed, deferred execution can be advantageous in terms of resource utilization.
Scenario: You are developing a Windows Forms application that needs to display and edit data from a database. Which ADO.NET component would you use to store and manage the data in a tabular format?
- DataSet
- SqlConnection
- SqlDataAdapter
- SqlDataReader
The DataSet class in ADO.NET is designed to store and manage data in a tabular format, making it suitable for use in Windows Forms applications where data needs to be displayed and edited. It provides a disconnected architecture, allowing data to be manipulated independently of the database.
What does "EF" stand for in the context of ADO.NET?
- Entity Facade
- Entity Factory
- Entity Flow
- Entity Framework
Entity Framework (EF) stands for Entity Framework. It is an Object-Relational Mapping (ORM) tool provided by ADO.NET, facilitating developers to work with relational data as domain-specific objects, eliminating the need for most of the data access plumbing code.
In ADO.NET Entity Framework, the [Key] attribute is often used to specify the ___________ property of an entity.
- Foreign
- Identity
- Navigation
- Primary
The [Key] attribute in Entity Framework is commonly applied to specify the identity property of an entity, indicating the property that uniquely identifies each instance of the entity.
When multiple users are modifying the same data concurrently, ___________ can help ensure data integrity.
- Constraints
- Isolation
- Locking
- Transactions
In scenarios where multiple users are modifying the same data concurrently, concurrency control mechanisms such as locking can help ensure data integrity by preventing conflicting modifications from occurring simultaneously.
Scenario: Your ADO.NET application is experiencing performance issues, and you suspect that connection pooling might be the cause. How can you investigate and optimize the connection pool settings?
- Adjust the "Min Pool Size" setting in the connection string
- Check the "Max Pool Size" setting in the connection string
- Evaluate the "Connection Lifetime" setting in the connection string
- Monitor the number of connections in use and the connection wait time
Monitoring the number of connections in use and the connection wait time is essential to understand the current utilization of the connection pool and identify any potential bottlenecks. By adjusting the pool size settings, such as "Max Pool Size" and "Min Pool Size," and evaluating parameters like "Connection Lifetime," you can optimize the connection pool for better performance.