47 ADO.NET Interview Questions (With Example Answers)

Updated 10 March 2023

ADO is an acronym for active data object and ADO.NET is the curation of .NET libraries and a cumulation of managed libraries that many .NET apps use for communicating a data source with a driver. Regarding the enterprise apps, a lot of data that is stored in databases that connect to them and to get to enterprise data and an interface is in use. Learning about which ADO questions a hiring manager is likely to ask can help you prepare well-thought out answers for your interview.

In this article, we explain why an interviewer might ask questions about ADO.NET and provide a list of common questions with examples to help you answer them.

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Why Does An Interviewer Ask ADO.NET Interview Questions?

Interviewers usually ask candidates ADO.NET interview questions because they want to ensure that the candidates have great knowledge and skills that are advantageous to the company's projects. They also want to ensure that the candidate can work well with other team members by checking the experience they have with the tools in ADO.NET. Another reason for asking may be to establish if a candidate can work with several frameworks.

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20 Basic ADO.NET Interview Questions

Here are basic questions a hiring manager may ask you in an interview:

  1. What is ADO.NET?

  2. What is ADO.NET connection model?

  3. Have you ever made an application with ADO.NET?

  4. Define API.

  5. What is boxing and unboxing?

  6. What namespace can you use to connect a data space in ADO.NET?

  7. Define OLEBD provider.

  8. What is data pooling?

  9. What are the components of ADO.NET data provider?

  10. Talk about SQLClient provider.

  11. What are the transaction types in ADO.NET?

  12. Name the DataSet XML methods.

  13. List the ADO.NET execute methods.

  14. Describe the ways to pick changes in a DataSet object.

  15. Explain the authentication technique that exists for ADO.NET.

  16. State the classes in System.Data Namespace.

  17. List the classes in System.Data.Common Namespace.

  18. Define DataAdapter in connection to ADO.NET.

  19. Explain the data providers that an ADO.NET framework uses.

  20. Which authentications exist in ADO.NET?

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20 Detailed ADO.NET Interview Questions

More detailed ADO.NET questions an interviewer can ask you as a candidate are:

  1. Discuss how to create a connection with an application and a source of data.

  2. When can an SQL server do an authentication technique?

  3. Explain what you can do with ADO.NET.

  4. What differences exist between OLEBD and SQLClient providers?

  5. What has to be in place for collection of pooling to occur?

  6. What are the differences between ADO.NET and ASP.NET?

  7. How do you end a database connection?

  8. How do you create and customise data?

  9. What is the importance of closing an application?

  10. What are the benefits of ADO.NET to a user?

  11. Why use stored procedures in ADO.NET?

  12. What are the differences between typed and untyped data sets?

  13. How do you load several tables in a dataset?

  14. What are the differences and similarities between DataSets and DataTables?

  15. What are the similarities and differences between DataReader and DataTable?

  16. When can you use boxing and unboxing?

  17. What feature do you call connected architecture?

  18. What feature do you call disconnected architecture?

  19. When do you use the method, ExecuteScaler()?

  20. Differentiate between Dataset.Clone() and Dataset.Copy().

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ADO.NET Questions And Their Sample Answers

The following are ADO.NET questions that a hiring manager might ask you:

1. How can a programmer make use of ADO.NET?

The hiring manager asks this question to assess your foundational knowledge of the topic and its relation to business. You can use examples of how you made use of the program in previous roles. When answering this question, state the uses of the software in relation to the goals and objectives of the company.

Example: ‘A programmer can use ADO.NET to create databases and similar applications. User applications can easily access data with the use of ADO.NET. For instance, in some industries, the software programming team can use it to create applications that connect with the stored data of their customers.'

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2. What are the major objects in the ADO.NET model?

Here, the hiring team is trying to determine how much knowledge you have about the basic features of the software. These tools are basic to database management and also programming, and you can apply them to different locations in programming. When answering this question, give a definition of the concepts with applicable examples.

Example: ‘DataReader and DataSet are the major objects in ADO.NET. Users make use of DataReader to get access to data from several sources, and once you have a database connection, you can use a DataReader. From Microsoft SQL server, I can read Tabular Data Streams. DataSet states the connection between tables in the set and it is a combination of data tables and other components.'

3. Explain the three layers in software architecture that ADO.NET uses.

The interviewer can use this question to assess whether you have proficient knowledge and your level of expertise with software architecture. Try to explain each of the layers and share brief examples of each. This can support your claims and allows you to elaborate on your knowledge.

Example: 'The three layers that ADO.NET use in software architecture are presentation, business logic and database. The presentation layer, which is also called the user interface layer, is where the users interact with the data and is similar to a landing page. For the business logic layer, the user or programmer builds workflow that determines how the application performs. In the database layer, the framework stores the data that controls the application.'

4. Describe the difference between a code-first and data-first approach.

By asking you to describe this difference, the interviewer can evaluate your ability to simplify the two concepts. The intention is to assess your knowledge about the connection between database construction and computer programmers. In answering, consider defining both approaches and providing an example to support your answer.

Example: 'For a code-first concept, the user creates the entities and builds the database around them. The approach is useful to create smaller databases where there is more control over the process. For a data-first concept, the user makes the database first and develops the entity models around it. I once used this method as an existing database or to make large ones.'

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5. What are the advantages of connection pooling?

With this question, the hiring manager aims to assess how you solve problems. Knowing the advantages shows the hiring manager that when problems arise, you can easily implement solutions that are advantageous to the organisation. To answer this question and demonstrate your expertise, you can provide an example of when you have solved a similar problem in previous roles.

Example: 'In a database, connection pooling takes common connections between items. The server draws a connection from the pool when a programmer requests access to a specific resource. Pooling helps databases to perform well by decreasing the amount of individual requests the server accepts. This ensures that the database works efficiently.'

6. What is the connection between LINQ and ADO.NET?

A hiring manager can ask you this question to determine what you know about database technologies. Your ability to discuss LINQ can demonstrate that you have extensive knowledge of ADO and other releavnt integrations. The interviewer may also use this as an opportunity to assess how you plan to maximise the software in the organisation.

Example: 'LINQ, which stands for language-integrated query, exists in the Microsoft.NET framework, and it enables users to address several query functions. To .NET languages, it adds some query expressions that enable programmers to build tools that accept data without delay and also without the use of a separate query language. The three LINQ technologies that ADO.NET use are DataSet, LINQ to Entities and LINQ to SQL, and they make available query capabilities in various ways.'

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7. What are the differences between Response.Expires and Response.ExpiresAbsolute?

This interview question is to prove the effect of techniques on the experience of the users of an application. The question might be to assess your knowledge of user experience. Try to explain the two concepts and give examples to explain your response.

Example: ‘These terms reveal the duration for which a webpage stays in a browser's cache after the user leaves the page. With Response.Expires, the programmer determines the amount of time that the cached version of a web page remains after the user leaves that page, whereas with Response.ExpiresAbsolute, the programmer selects a date and time at which the cached page expires. For instance, after a user leaves a page, the cached version might remain for 30 minutes, or it might end at midnight on a specific day.'


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Please note that none of the companies, institutions or organisations mentioned in this article are associated with Indeed.

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