In LINQ to Objects, what type of data source does it query?
- Arrays and Lists
- Relational Databases
- Web Services
- XML Files
LINQ to Objects queries in-memory collections such as arrays and lists. It's primarily used for querying data structures within the application's memory rather than querying external data sources like databases or web services.
When optimizing LINQ queries for performance, which of the following should you consider?
- Deferred Execution
- Eager Loading
- Immediate Execution
- Lazy Loading
When optimizing LINQ queries for performance, consider using deferred execution. Deferred execution postpones the execution of a LINQ query until the query is iterated over or materialized. This can help minimize the number of database round-trips and optimize memory usage.
Scenario: You need to configure the connection pool for an application that requires multiple concurrent database connections. What factors should you consider while setting the connection pool parameters?
- Database server capacity and limitations
- Maximum number of concurrent users accessing the application
- Network latency between the application server and the database server
- Size of the application's user base
When configuring the connection pool for an application requiring multiple concurrent database connections, it's crucial to consider factors such as the maximum number of concurrent users accessing the application and the database server's capacity and limitations. These parameters help determine the optimal settings for the connection pool size to ensure adequate resources for all concurrent connections without overloading the database server.
In ADO.NET, what is the difference between a DataView and a DataTable?
- DataTable represents a single table of in-memory data with rows and columns.
- DataView is primarily used for database operations, while DataTable is used for XML operations.
- DataView is read-only and cannot be updated, whereas DataTable allows modification of data.
- DataView provides a dynamic view of data with sorting, filtering, and searching capabilities.
DataViews and DataTables serve different purposes in ADO.NET. A DataTable represents a single table of in-memory data, while a DataView provides a dynamic view of data from one or more DataTables with sorting, filtering, and searching capabilities.
Connection pooling in ADO.NET helps in ___________ database connections for better performance.
- Limiting
- Managing
- Reducing
- Sharing
Connection pooling in ADO.NET involves reducing the number of times connections need to be opened and closed by reusing existing connections, which ultimately improves performance by reducing overhead.
Scenario: You are developing an application that needs to interact with a SQL Server database. Which component of Entity Framework would you use to define the data model and work with the database?
- Code-First Approach
- DbContext
- DbSet
- Entity Data Model
DbContext serves as the primary class in Entity Framework for interacting with the database. It represents a session with the database and can be used to query and save instances of your entities. It also allows you to define the data model through entity classes and their relationships. DbSet, on the other hand, represents a collection of entities of a specific type in the context. Entity Data Model is a conceptual model that describes the structure of data, but DbContext is the component used to interact with the database. Code-First Approach is a methodology for creating the data model through code rather than using a visual designer, but DbContext is the component that enables this approach within Entity Framework.
What is the purpose of the SqlDataReader class in ADO.NET?
- Executes SQL commands and returns a result set
- Provides a way to read a forward-only stream of rows from a SQL Server database
- Represents a disconnected architecture for interacting with a database
- Retrieves data from the database and populates a DataSet
The purpose of the SqlDataReader class in ADO.NET is to provide a way to read a forward-only stream of rows from a SQL Server database. It enables efficient data retrieval and processing by sequentially reading data from the database without the need to cache the entire result set in memory.
In Code-First development, how are database tables created based on entity classes?
- By defining entity classes and configuring them with attributes or fluent API, then using migrations to create or update the database schema
- By directly creating database tables in SQL Server Management Studio and mapping them to entity classes
- By generating entity classes from an existing database schema using the Entity Data Model Wizard
- By utilizing scaffolding tools to generate entity classes from database tables automatically
Code-First development in Entity Framework allows developers to define entity classes and their relationships in code without having to design the database schema upfront. This is typically achieved by defining entity classes and configuring them with attributes or fluent API to specify details such as table names, column names, and relationships. Developers can then use migrations to create or update the database schema based on these entity classes.
In a parameterized query, what does a parameter represent?
- A column name in a database table
- A predefined SQL command
- A stored procedure
- A value that is provided by the user at runtime
In a parameterized query, a parameter represents a value that is provided by the user at runtime. This allows for dynamic input while still preventing SQL injection attacks by separating the data from the SQL command. Parameters are placeholders that are replaced with user-supplied values when the query is executed, thereby reducing the risk of malicious input altering the query's behavior.
Data binding in WinForms allows you to establish a link between a data source and a ___________ control.
- ComboBox
- DataGrid
- DataGridView
- TextBox
Data binding in WinForms allows you to establish a link between a data source, such as a database or a collection, and a control that can display data. The DataGridView control is used to display and edit tabular data and is commonly used for data binding in WinForms applications.