Scenario: You are developing an application that needs to query a list of customer objects stored in memory. Which LINQ technology would you choose for this task?
- LINQ to Entities
- LINQ to Objects
- LINQ to SQL
- LINQ to XML
LINQ to Objects is the appropriate choice for querying in-memory collections, such as lists of customer objects. It provides powerful querying capabilities against in-memory data structures.
To prevent SQL injection attacks, it is recommended to use ________ queries.
- Dynamic
- Embedded
- Parameterized
- Prepared
Parameterized queries are a recommended practice to prevent SQL injection attacks. By using parameters, the values provided by users are treated as data rather than executable code, thereby mitigating the risk of injection attacks.
Using a database-specific data provider, such as SqlClient, can result in ___________ performance compared to generic providers.
- Improved
- Deteriorated
- Similar
- Unpredictable
The correct option is Improved. Using a database-specific data provider, like SqlClient for SQL Server databases, often results in improved performance compared to generic providers such as OLEDB. This is because database-specific providers are optimized to leverage the features and capabilities of a particular database system, leading to better efficiency and resource utilization. Generic providers may introduce additional layers of abstraction and overhead, which can impact performance negatively.
To retrieve different data types from a data reader, you can use the _______ method.
- GetField()
- GetString()
- GetType()
- GetValue()
To retrieve different data types from a data reader, you can use the GetValue() method. This method returns the value of the specified column as an object, which you can then cast to the appropriate data type based on the data stored in the database.
In LINQ to SQL, what is the role of the DataContext class in query optimization?
- Caching query results for faster access
- Managing database connections and transactions
- Optimizing the execution plan of generated SQL queries
- Translating LINQ queries into SQL queries
In LINQ to SQL, the DataContext class plays a crucial role in query optimization by translating LINQ queries into SQL queries that are executed against the database. It ensures that LINQ queries are efficiently converted into optimized SQL queries, thereby enhancing performance.
What is the primary purpose of modifying data in datasets?
- To delete data
- To insert data
- To read data
- To update data
Modifying data in datasets primarily involves updating existing data to reflect changes made by users or applications. This can include changing values, correcting errors, or adding new information. Updating data ensures that the dataset remains accurate and up-to-date with the latest information.
The Rollback method in ADO.NET is used to ___________ a transaction.
- Abort
- Begin
- Commit
- Undo
The Rollback method in ADO.NET is used to undo or cancel a transaction, reverting any changes made since the transaction began.
When binding data to a ListBox, what is the significance of the DataValueField property?
- It specifies the data source to bind to the ListBox
- It specifies the field from the data source to use as the text for the ListBox items
- It specifies the field from the data source to use as the value for the ListBox items
- It specifies the format for displaying the data in the ListBox
When binding data to a ListBox, the DataValueField property is significant as it specifies the field from the data source to use as the value for the ListBox items. This means that when an item is selected from the ListBox, the corresponding value from this specified field is retrieved and can be used in further processing or manipulation of the selected item.
What is the difference between a DataRow and a DataTable in ADO.NET?
- DataAdapter
- DataRow
- DataTable
- DataView
A DataRow represents a single row of data within a DataTable, whereas a DataTable represents the entire table structure, including multiple rows and columns.
Scenario: Your Entity Framework application is encountering concurrency conflicts when updating data. What strategies can you implement to handle these conflicts effectively?
- Use optimistic concurrency by configuring the Entity Framework to check if the record has been modified by another user before saving changes.
- Use pessimistic concurrency by locking the record during the update process to prevent other users from modifying it simultaneously.
- Ignore concurrency conflicts and overwrite the changes made by other users during the update process.
- Rollback the transaction and notify the user to retry the operation later.
In Entity Framework, to handle concurrency conflicts effectively, you can implement strategies such as optimistic concurrency. This involves configuring Entity Framework to check if the record has been modified by another user before saving changes. Other options like pessimistic concurrency can lead to performance issues and locking conflicts. Ignoring conflicts or rolling back transactions without proper handling can result in data inconsistency and user frustration.