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.
ADO.NET provides mechanisms to automatically ___________ and ___________ connections when they are no longer needed.
- Close; Dispose
- Connect; Disconnect
- Open; Close
- Open; Dispose
In ADO.NET, the methods Open() and Dispose() are used to respectively establish and release connections. The Open() method opens a connection to a data source, while the Dispose() method releases the resources used by the connection.
Scenario: Your application requires real-time updates of data in the UI whenever changes occur in the database. Which type of data binding would be suitable for this scenario, and why?
- Two-way data binding
- One-way data binding
- Observer pattern
- Three-way data binding
The correct option is Observer pattern. In this scenario, where real-time updates are needed in the UI, the Observer pattern would be suitable. The Observer pattern allows objects to subscribe to changes in other objects and receive notifications when those changes occur. This enables real-time updates in the UI whenever changes happen in the database, ensuring synchronization between the database and the UI. Two-way data binding allows updates from UI to data source and vice versa, but it might not provide real-time updates. One-way data binding only updates the UI from the data source, and Three-way data binding is not a standard concept in ADO.NET.
To add a new row to a DataTable in a dataset, you typically use the ___________ method.
- Insert
- Create
- Append
- Add
The correct option is "Add". When adding a new row to a DataTable in a dataset, the common method used is the Add method of the DataRow collection.
You are working with a SqlDataReader to fetch data from a SELECT statement. What should you consider when iterating through the result set?
- Check for null values
- Close the connection after iteration
- Read data in sequential order
- Use asynchronous methods
The correct option is Read data in sequential order. When working with a SqlDataReader, it's essential to iterate through the result set in a sequential manner using methods like Read(). This allows you to retrieve each row of data one at a time, which is efficient for processing large result sets without loading the entire data into memory at once.
When using data binding in WinForms, what is the role of the BindingSource component?
- Acts as a bridge between the data source and controls, facilitating synchronization
- Handles user interactions with the UI controls
- Manages connections to the database and executes SQL queries
- Provides visual representation of the data in a grid view
The BindingSource component acts as a bridge between the data source (such as a dataset or data table) and the controls on a form. It facilitates synchronization of data between the controls and the underlying data source, making it easier to manage and manipulate data in WinForms applications.
Data binding can simplify UI development by automatically synchronizing ___________ and data source.
- UI controls
- UI elements
- User interface
- Presentation components
The correct option is UI controls. Data binding automatically synchronizes the data displayed by UI controls with data stored in a data source, such as a database or a collection. By binding UI controls directly to data sources, developers can simplify UI development and ensure that the user interface reflects changes in the underlying data automatically.
In ADO.NET Entity Framework, which attribute is commonly used to specify the table to which an entity should be mapped?
- DatabaseTable
- Entity
- MappingTable
- Table
Table
What is distributed transaction management in ADO.NET, and when might it be necessary?
- Coordinates transactions within a single database.
- Ensures data consistency within a single database.
- Facilitates transactions across multiple databases or systems.
- Manages concurrent transactions within a single application.
Distributed transaction management in ADO.NET allows for transactions to span multiple databases or systems, ensuring data consistency across them. This becomes necessary in scenarios where data needs to be updated or retrieved from multiple sources, and maintaining integrity across these sources is crucial.
In Entity Framework, what is a DbSet?
- A collection-like object representing a table in the database that can be queried and modified
- A database context class that represents the connection to the database
- A query language used to retrieve data from the database
- An attribute used to specify the primary key of an entity class
In Entity Framework, a DbSet represents a collection-like object that corresponds to a table in the database. It allows developers to query and manipulate data in that table using LINQ queries and methods provided by Entity Framework. Each DbSet property in a DbContext represents a specific entity type and corresponds to a table in the underlying database.