How can you create a filtered view of data from a DataSet using DataViews?
- Use the DataView.Filter method to apply a filter expression to the DataView.
- Use the DataView.RowFilter property to specify filter criteria based on column values.
- Use the DataView.RowStateFilter property to filter rows based on their state (e.g., Added, Modified, Deleted).
- Use the DataView.Select method to select specific rows from the DataView.
To create a filtered view of data from a DataSet using DataViews, you can use the RowFilter property of the DataView. This property allows you to specify filter criteria based on column values, thereby creating a filtered view of the data according to your requirements.
One of the advantages of data binding is that it helps in keeping the UI and ___________ in sync.
- Business logic
- Data manipulation
- Database
- Presentation
One of the advantages of data binding is that it helps in keeping the UI and presentation in sync with the underlying data, ensuring consistency between what is displayed and what is stored.
Scenario: In a LINQ to DataSet query, you encounter the concept of deferred execution. Explain what deferred execution means and provide an example of when it might be advantageous.
- Execution of query happens after modifying the underlying data.
- Execution of query happens in parallel with other operations.
- Execution of query is immediate and results are generated as soon as the query is executed.
- Execution of query is postponed until the results are actually requested or iterated over.
Deferred execution means that the execution of the LINQ query is delayed until the results are actually needed. This postponement allows for better performance optimization, especially when dealing with large datasets, as it avoids unnecessary computations until the results are required. For example, when dealing with complex queries or when the query result is not immediately needed, deferred execution can be advantageous in terms of resource utilization.
Scenario: You are developing a Windows Forms application that needs to display and edit data from a database. Which ADO.NET component would you use to store and manage the data in a tabular format?
- DataSet
- SqlConnection
- SqlDataAdapter
- SqlDataReader
The DataSet class in ADO.NET is designed to store and manage data in a tabular format, making it suitable for use in Windows Forms applications where data needs to be displayed and edited. It provides a disconnected architecture, allowing data to be manipulated independently of the database.
To optimize LINQ queries for performance, you can use the ___________ method to reduce the number of database calls.
- Aggregate
- AsQueryable
- Join
- Select
To optimize LINQ queries for performance, you can use the AsQueryable method to reduce the number of database calls. This method converts an IEnumerable collection to an IQueryable collection, allowing the query to be executed on the database server instead of in-memory. This can lead to significant performance improvements, especially when dealing with large datasets or complex queries.
To improve LINQ query performance, you can use the DataLoadOptions class to specify ___________ loading.
- Eager
- Lazy
- Deferred
- Immediate
Eager loading retrieves all related data at once, which can enhance performance by reducing the number of database calls. This is done using the LoadWith method of DataLoadOptions.
When executing an INSERT command, you can use ___________ to specify the values to be inserted.
- INTO clause
- SELECT clause
- VALUES clause
- WHERE clause
In an INSERT command in SQL, the VALUES clause is used to specify the values to be inserted into the specified columns of a table. It allows you to define the data that will be added to the table.
DataGrid and DataGridView controls are often used for displaying data in a ___________ format.
- Graphical
- Hierarchical
- Tabular
- Textual
DataGrid and DataGridView controls are often used for displaying data in a Tabular format. These controls provide a grid-like structure that allows data to be displayed in rows and columns, making it suitable for presenting tabular data retrieved from databases.
Scenario: Your application uses Entity Framework extensively, and you notice that some queries are slow. What steps can you take to identify and address performance bottlenecks in Entity Framework?
- Analyzing generated SQL queries for inefficiencies
- Ensuring proper indexing on database tables
- Implementing caching mechanisms to reduce database hits
- Using database profiling tools to identify slow queries
Analyzing generated SQL queries helps identify any inefficient queries that might be causing performance issues. Database profiling tools provide insights into query execution times and help pinpoint slow queries. Ensuring proper indexing on database tables can significantly improve query performance. Implementing caching mechanisms reduces the need for frequent database hits, enhancing overall performance.
What is the role of the CommandTimeout property in an ADO.NET command object?
- Specifies the maximum number of retries for the command execution
- Specifies the maximum time in seconds for the command to execute before throwing an exception
- Specifies the minimum time in milliseconds for the command to execute
- Specifies the wait time in milliseconds between command executions
The CommandTimeout property in an ADO.NET command object specifies the maximum time in seconds for the command to execute before throwing a timeout exception. It allows developers to control the duration of command execution, preventing long-running queries from causing performance issues or blocking the application. By setting an appropriate CommandTimeout value, developers can balance the need for timely responses with the complexity of database operations, ensuring optimal application responsiveness and user experience.