Scenario: In a LINQ query, you encounter the orderby clause. What is the purpose of this clause, and how does it affect the query results?
- It filters the elements based on a specified condition.
- It groups the elements based on a common key.
- It joins two or more collections based on a related key.
- It sorts the elements in ascending order based on a specified key.
The purpose of the orderby clause in a LINQ query is to sort the elements in ascending order based on a specified key. This clause arranges the query results alphabetically or numerically according to the specified key, allowing for organized presentation of data.
Scenario: A colleague suggests using plain SQL statements instead of parameterized queries for simplicity. What would you advise them regarding SQL injection risks?
- Advise against using plain SQL statements
- Encourage using input validation
- Recommend using stored procedures
- Suggest using a web application firewall
Using plain SQL statements exposes the application to SQL injection vulnerabilities. Parameterized queries provide a more robust defense against such attacks. Recommending stored procedures can be a good practice, but it's not as directly related to preventing SQL injection as parameterized queries. Web application firewalls and input validation are important layers of defense but should not replace proper SQL injection prevention measures.
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.
Scenario: You are developing an application that needs to execute a complex SQL query with parameters. Which ADO.NET object would you use for this task?
- SqlCommand
- SqlConnection
- SqlDataAdapter
- SqlDataReader
SqlCommand is used to execute SQL commands, including complex queries, with parameters. It allows for parameterized queries, reducing the risk of SQL injection attacks and enhancing performance by reusing execution plans.
When you bind data to a DropDownList control, what property is typically used to display the items to the user?
- DisplayMember
- SelectedValue
- Text
- Value
When binding data to a DropDownList control in ADO.NET, the DisplayMember property is typically used to specify which property of the data source objects should be displayed as the items in the DropDownList. This property allows customization of the displayed text while binding data to the control.
LINQ to SQL provides a convenient way to map database ___________ to .NET objects.
- Tables
- Rows
- Columns
- Views
The correct option is 'Tables'. LINQ to SQL enables developers to map database tables directly to .NET objects, making it easier to work with relational data in an object-oriented manner. Each table in the database corresponds to a class in the LINQ to SQL data context, and each row in the table is represented by an instance of that class. This mapping simplifies data access and manipulation tasks.