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.
Scenario: When you update data in a dataset, the changes should also be reflected in the underlying database. What ADO.NET component is responsible for syncing these changes with the database?
- DataAdapter
- SqlCommand
- SqlConnection
- SqlDataReader
The DataAdapter in ADO.NET serves as a bridge between a dataset and a database. It facilitates communication between the dataset and the database by executing SQL commands (such as INSERT, UPDATE, DELETE) and updating the database with changes made to the dataset. Hence, it ensures synchronization of data between the dataset and the underlying database.
What is optimistic concurrency, and how does it relate to modifying data in datasets?
- It locks the database during data modification
- It assumes that no other user will interfere during data modification
- It requires explicit locking of data before modification
- It rolls back changes if conflicts occur during data modification
The correct option is It assumes that no other user will interfere during data modification. Optimistic concurrency is a strategy in ADO.NET where it assumes that no other user will interfere during data modification. It allows multiple users to access and modify the same data simultaneously without locking the database. If conflicting changes occur, it's typically handled during data submission. The other options do not accurately describe optimistic concurrency.
DataRelations are used to create ___________ between tables in a dataset.
- Constraints
- Indexes
- Joins
- Relationships
DataRelations in ADO.NET allow you to establish relationships between DataTables in a DataSet. These relationships define how the tables are related to each other, enabling operations like parent-child data retrieval and maintaining data integrity across tables.
In LINQ, what does the acronym "SQL" represent?
- Search Query Language
- Selective Query Language
- Sequential Query Language
- Structured Query Language
In LINQ, "SQL" represents "Structured Query Language", the standard language for relational database management systems.
Which ADO.NET data reader is used specifically for working with SQL Server databases?
- MySqlDataReader
- OleDbDataReader
- OracleDataReader
- SqlDataReader
The SqlDataReader is specifically designed for working with SQL Server databases in ADO.NET. It provides a forward-only, read-only stream of data from a SQL Server database, allowing efficient retrieval and processing of query results. Unlike other data readers, SqlDataReader is optimized for the SQL Server data provider, providing better performance and functionality when working with SQL Server databases.