Scenario: You want to implement data retention policies in your application by deleting old records from a database table. Which ADO.NET command would you use to perform this task?
- SqlCommand.ExecuteNonQuery()
- SqlCommand.ExecuteQuery()
- SqlCommand.ExecuteScalar()
- SqlCommand.ExecuteXmlReader()
SqlCommand.ExecuteNonQuery() is commonly used to execute non-query commands, including data manipulation language (DML) queries like DELETE statements. This command is suitable for tasks that modify the database without returning any data, making it ideal for deleting old records from a database table as part of a data retention policy.
You are tasked with designing a data access layer for a new project that involves LINQ to Entities. What considerations should be kept in mind when designing the Entity Framework model?
- Proper Entity Relationships and Navigation Properties
- Avoiding Error Handling in Queries
- Using Stored Procedures for All Queries
- Using Anonymous Types for Query Results
The correct option is "Proper Entity Relationships and Navigation Properties." It's crucial to establish correct relationships between entities and utilize navigation properties for efficient querying and data retrieval in LINQ to Entities.
Which isolation level ensures that other transactions cannot read uncommitted changes made by the current transaction?
- Read Committed
- Read Uncommitted
- Repeatable Read
- Serializable
The "Read Uncommitted" isolation level allows a transaction to read data that has been modified but not yet committed by other transactions. It does not provide protection against dirty reads, non-repeatable reads, or phantom reads.
What are some advanced features or functionalities that you can implement using DataGrid or DataGridView controls?
- Animation effects, real-time collaboration features, and multimedia integration.
- Augmented reality interactions, virtual reality simulations, and 3D visualization.
- Machine learning algorithms for predictive analysis and natural language processing.
- Sorting, filtering, grouping, and hierarchical data representation.
DataGrid and DataGridView controls offer a wide range of advanced features and functionalities, including sorting, filtering, grouping, and hierarchical data representation. These capabilities empower developers to create interactive and feature-rich applications that enhance data exploration and analysis for end users.
When using a data reader, what is the typical sequence of operations for reading data?
- Execute the query, Open the connection, Close the connection, Read the data
- Execute the query, Read the data, Close the connection, Open the connection
- Open the connection, Close the connection, Execute the query, Read the data
- Open the connection, Execute the query, Read the data, Close the connection
When using a data reader, the typical sequence of operations involves opening the connection to the database, executing the query to retrieve data, reading the data sequentially, and then closing the connection. This sequence ensures efficient data retrieval and resource management.
Parameters in non-query commands help prevent ___________ attacks.
- Cross-Site Request Forgery (CSRF)
- Cross-Site Scripting (XSS)
- Denial of Service (DoS)
- SQL Injection
SQL Injection attacks occur when malicious SQL code is inserted into input fields of an application, potentially allowing an attacker to execute unauthorized SQL commands. By using parameters in non-query commands, such as prepared statements or parameterized queries, input values are treated as data rather than executable code, thereby reducing the risk of SQL Injection attacks.
When using the Repeater control, what is responsible for defining the layout of the repeated items?
- FooterTemplate
- HeaderTemplate
- ItemTemplate
- SeparatorTemplate
In the context of the Repeater control, the ItemTemplate is responsible for defining the layout of each repeated item. It allows you to specify the structure and appearance of the individual items being repeated. For example, you can define HTML markup or controls to display data from the data source.
In LINQ to Entities, the ___________ operator is used to combine two or more sequences into a single result.
- Concatenate
- Join
- Merge
- Union
In LINQ to Entities, the Concatenate operator is used to combine two or more sequences into a single result. It returns a new sequence that contains elements from the input sequences.
Scenario: You are tasked with creating a custom data provider for a niche database system. What factors should you consider during the development of this custom provider?
- Database Compatibility
- Error Handling
- Performance Optimization
- Security Measures
SqlConnection is the ADO.NET class responsible for managing database connections. It represents a connection to a SQL Server database. It is used to open, close, and manage the connection to the database server.
What is the role of the CommandBuilder class in ADO.NET?
- It facilitates the creation of database commands
- It generates SQL statements automatically based on changes made to a DataSet
- It manages connections to the database
- It provides a bridge between a .NET application and a database
The CommandBuilder class in ADO.NET is responsible for automatically generating SQL statements (such as INSERT, UPDATE, DELETE) based on changes made to a DataSet, simplifying the process of updating data in a database. This automation reduces the amount of manual coding required, improving development efficiency.
Pessimistic concurrency locks data ___________.
- Concurrently
- Proactively
- Reactively
- Temporarily
Pessimistic concurrency locks data proactively, meaning it locks the data before any modification attempt is made. This approach ensures that only one transaction can access and modify the data at a time, thus preventing concurrency conflicts by holding exclusive locks on the data for the duration of the transaction.
In ADO.NET, what is the difference between a local transaction and a distributed transaction?
- A local transaction can only be used with SQL Server, while a distributed transaction works with any database.
- A local transaction involves a single database, while a distributed transaction spans multiple databases or systems.
- A local transaction is faster than a distributed transaction.
- A local transaction is managed entirely by the application, while a distributed transaction requires coordination by a distributed transaction coordinator.
The key difference between a local transaction and a distributed transaction in ADO.NET lies in their scope. A local transaction involves operations within a single database, whereas a distributed transaction extends across multiple databases or systems. A distributed transaction also requires coordination by a distributed transaction coordinator, which adds complexity compared to local transactions.