Scenario: You are working with an Oracle database and need to handle NULL values gracefully while reading data. Which method of the OracleDataReader would you use for this purpose?
- GetOracleValue()
- GetString()
- GetValue()
- IsDBNull()
The IsDBNull() method of the OracleDataReader class allows for the graceful handling of NULL values in an Oracle database. It returns true if the specified column contains a NULL value, enabling developers to handle NULLs appropriately in their application logic. GetValue() retrieves the value of the specified column, GetString() returns the value of the specified column as a string, and GetOracleValue() is not a valid method in OracleDataReader.
What is data binding in ADO.NET used for?
- Binding data to controls
- Creating stored procedures
- Establishing a connection to the database
- Executing SQL queries
Data binding in ADO.NET refers to the process of connecting data from a data source to controls such as grids, textboxes, or dropdown lists. It enables automatic synchronization of data between the user interface and the underlying data source, simplifying development and enhancing user interaction.
LINQ provides a unified and concise way to query and manipulate ___________ data.
- Object
- Relational
- SQL
- XML
LINQ, or Language Integrated Query, allows developers to query and manipulate objects in various data sources, including objects in memory.
In ADO.NET, the RowVersion column is used to track ___________.
- Data concurrency
- Data integrity
- Data synchronization
- Data validation
The RowVersion column in ADO.NET is used to track data concurrency, enabling efficient detection of changes and conflicts between different users.
In your ASP.NET application, you want to display a list of products from a database and allow users to edit them. What type of data binding would be suitable for this scenario, and why?
- Two-way data binding
- Data binding with LINQ to SQL
- Data binding with DataReader
- Data binding with DataList control
Two-way data binding would be suitable for this scenario. This type of data binding allows changes made in the UI to automatically update the underlying data source, and vice versa. In an ASP.NET application, this means users can edit the product list directly in the UI, and those changes will be reflected back to the database. Two-way data binding simplifies the development process and improves user experience by ensuring seamless interaction between the UI and the data source. The other options either lack support for bidirectional data flow or involve more complex implementations.
Your application requires efficient loading of related data when querying a database using LINQ to Entities. Which method or approach would you employ to achieve this?
- Eager Loading
- Lazy Loading
- Explicit Loading
- Deferred Loading
The correct option is "Eager Loading." In this approach, related data is loaded along with the primary entities, reducing subsequent database trips and enhancing performance in querying related data.
What is the key difference between a data provider and an ADO.NET managed provider?
- The connection pooling mechanism
- The data source supported
- The database type supported
- The method of data access
A data provider in .NET is responsible for interacting with a specific data source, such as SQL Server or Oracle, while an ADO.NET managed provider is responsible for managing the connection and communication between the .NET application and the underlying database. The key difference lies in the handling of the data source, with the data provider focusing on data access and the managed provider focusing on managing the connection and communication.
The RowFilter property in a DataView is typically used to apply ___________ to the data.
- Aggregation
- Constraints
- Filtering
- Sorting
The RowFilter property in a DataView is used to apply filtering criteria to the data, allowing you to display only the rows that meet specific conditions. It helps in refining the view of data according to the user's needs.
Which ADO.NET control is commonly used for displaying database records in a tabular format?
- ComboBox
- DataGridView
- ListBox
- TextBox
The DataGridView control in ADO.NET is commonly used for displaying database records in a tabular format. It provides a grid-like interface that can be easily populated with data from a database, allowing users to view and interact with the data in a structured manner.
To execute a LINQ to Entities query and retrieve the results, you often use the ___________ method.
- ExecuteNonQuery
- ExecuteQuery
- ExecuteReader
- ToList
To retrieve results from a LINQ to Entities query, you commonly use the ToList() method. This method executes the query against the database and materializes the results into a list of objects in memory. It is essential for fetching data from the database and working with it within the application, enabling developers to perform further processing or display the data to users as needed.