Microsoft’s Entity Framework (EF) is an open-source ORM (Object-Relational Mapper). It gives developers the ability to deal with.NET apps and other domain-specific objects. By offering tables and columns, it helps to simplify mapping between different items inside the software. Below is a list of technical and general questions involved in an entity framework interview.
1. What Is The Entity Framework Code First Approach?
We avoid using the Entity Framework Visual Designer in the Code First methodology. In other words, the EDMX file is not part of the solution. So you now have total control over both the context and entity classes.
2. What Does A Dbcontext Class Do?
A DbContext represents the database connection and a set of tables, whereas DbSet represents the tables themselves. The DbContext lets you use a connection string to connect your model attributes (probably using Entity Framework) to your database.
When you later want to refer to a database in your controller to handle data, you use the DbContext.”
3. Can You Describe Lazy Loading In More Detail?
Lazy loading is a technique in which things are loaded on demand rather than all at once. Consider a case where the Customer and Address objects have 1 to many associations. Let’s imagine you’re viewing the customer data but don’t want address info loaded right now. However, before using the address object, you need to load address data from the database.”
4. In Entity Framework, How Can We Deal With Concurrency?
The concurrency problem in the entity framework is solved by employing optimistic locking. To use optimistic locking, right-click on the EDMX designer and choose Fixed as the concurrency option. You should receive an Optimistic Concurrency Exception error anytime we have a concurrency problem.
5. What Are Entity Framework POCO Classes?
POCO is an abbreviation for Plain Old C Object. EDMX generates classes cluttered with entity tags. We frequently want to use simple.NET groups and integrate them with the Entity Framework. In other words, you can create a simple.NET class and load it using the entity context object.
6. How Do I Connect The Entity Framework To The SQL Server?
The following methods are available for connecting the entity framework to the SQL Server:
- By right-clicking on the application, you can create a class.
- Create the class variables and assign the necessary properties.
- Conserve the class. In the same way, add another group.
- Create a new folder for the Framework Dynamic Link Library by right-clicking (DLL)
- The folder is renamed to meet the needs of the developer.
- Before adding any framework, save the application.
- Right-click the Program.cs file and choose the appropriate properties to copy the program’s address.
- Copy the required address for adding the DLL framework by right-clicking on the program’s window.
- After locating the folder and adding the Entity framework DLL, right-click on the references and then add it to browse the DLL framework.
- The application configuration file was added.
- The App should be used to declare, the DB path name and database name. config file
- In the main program, the context and objects are declared.
- To run the program, press F5.
7. What Is The Function Of The Entity Client Data Provider?
The Entity Client Data Provider’s responsibility is to convert LINQ to Entities or Entity SQL queries to SQL queries that the underlying database understands. Finally, this communicates with ADO.NET Data Provider, which communicates with the database.
8. What Precisely Is Optimistic Locking?
Optimistic locking is a strategy that involves reading a record, noting a version number, and ensuring that the version hasn’t changed before writing the record back. When you write it, you filter the version update to ensure it’s atomic. (that is, it hasn’t been updated between the time you check the version and write the record to the disk) and update the version in a single hit.
9. What Is LINQ, And What Does It Have To Do With Entity Framework?
LINQ is a C# syntax for writing SQL-style queries. LINQ can query data stores, including databases, XML files, and C# collections. Entity Framework queries are written in LINQ syntax.
10. Is Entity Framework More Efficient Than Ado Net?
Ado.net is faster than Entity Framework because ado.net allows you to run SQL queries directly on the database. However, the entity framework generates a query based on the data you want to import, table relations, and loading selection, and these queries are typically slower than pure SQL queries.
One of the primary causes of this lag is the mapping of data retrieved from the database as a result of this query, and the complex SQL query generated by the entity framework.
11. What Do The Terms Pluralize And Singularize Mean In The Context Of Entity Framework?
The tables in the entity framework database are converted into classes used to code in the database first approaches. When creating groups from database tables, the Pluralize feature allows you to pluralize the name. In other words, if we have a table named “customer,” the class name in the code will be “customers.” This will keep the database table names from clashing with others from existing classes in our project.
12. What Is The Entity Framework’s Architecture?
Entity Framework’s architecture includes the following components, which are as follows:
EDM (Entity Data Model): EDM consists of three components: a conceptual model, a storage model, and mapping. The conceptual model, which is independent of the database table, aids in the inclusion of the model class and their relationships. The storage model is a component of the database design model that aids in the organization of tables, stored procedures, views, relationships, and keys. Mapping refers to information about the conceptual model’s mapping to the storage model.
LINQ to Entities (L2E): L2E is a query language that allows queries against an object to return entities based on definitions in the conceptual model.
Entity SQL: Entity SQL is a more complex query language than L2E.
Object Service: The object service is the database’s entry point for accessing and returning data. It is in charge of converting the data returned by an entity client data provider to an entity object structure.
Provider of Entity Client Data: This layer aids in the conversion of LINQ-to-Entities queries to SQL queries that the database recognizes. It also aids communication with the ADO.Net data provider when sending or retrieving data from the database.
Provider of Internet Data: To communicate with the database, this layer employs standard ADO.Net.
13. How Does Entity Validation Work?
Entity validations are performed at the controller or context levels. Controls at the controller level can be performed manually or with the help of an external tool. Manual checks are ineffective because they necessitate the creation of new code for each new method. As a result, when validating at the controller level, it makes more sense to use an external tool. One of the most common is Fluent Validation. You can prevent the entry of larger or smaller values by using the rules you define in your properties, depending on the length, and limit you set. You can also specify what message should be displayed when a parameter violates these rules.
14. In Entity Framework, How Do You Run Stored Procedures?
The entity framework enables you to manage database operations without writing SQL queries. However, because of its flexible structure, there is a method for running pure SQL queries whenever needed. This method is used to run store procedures. Bypassing the name of our store procedure to this method, we can run the SQL query as a parameter. This is repeated with the Database utility on our DbContext class.
15. List The Inheritance Types Supported By The Entity Framework?
The Entity Frameworks have supported several types of inheritance, which are as follows:
TPT, or Table per Type, is a technique for depicting a separate or distinct table for each domain class. TPC, or Table per Concrete Class, shows a single table for a single concrete class, but not the abstract class. As a result, if the abstract class is inherited by an infinite number of concrete classes, the abstract class’s features become a fragment of every table of the concrete class. In a relational database, there are few patterns of class hierarchy that are depicted for mapping. TPT and TPH are two of the most popular.
16. What Exactly Are Transactions?
Assume you made changes to the database tables. Whether the operation is an insert, update, or delete. At this point, you should use transactions if your transaction will affect one or a few different points and you may want to undo all of the transactions in case an error occurs at any of these points.
17. In Entity Framework, How Do You Return Multiple Sets Of Results?
By implementing the following script file, STOREDB.sql, in SQL Server Management Studio or SSMS or Visual Studio, one can create the database in the SQL Server or Local DB and occupy the tables.
The script is implemented by entering the two collected processes into the database. Select those procedures from the Add tab’s functions list.
The Model Browser is accessed by right-clicking on any blank area of the Entity Framework developer. Replace GetProductCM Result with Product SprocResult. The StoreDBModel.edmx file should be saved. Learn about the FunctionImportMapping nodes in edmx: Mapping/../En.
18. What Exactly Are Data Annotations?
Data annotations are structures that allow us to assign values to the code side of our database fields based on rules. Overwriting properties specify them. Fields that do not comply with the laws outlined in these notations will cause the code to throw an error when the database changes are saved and will prevent the operation from taking place.
19. In The Entity Framework, What Is The Model-First Approach?
The model classes and their relationships are created first in the Entity Framework’s Model First approach with the help of the ORM. The model is then used to generate the physical database. As a result, an entity and relation diagram is changed into a code model.
20. How Can We Mark A Field/Property As The Primary Key If We Have Not Followed Proper Conventions In The Code First Approach?
An aspect of the EF Code First approach is that we must follow the proper convention for a primary key, which means Entity Framework expects ID combined with Entity Name. In the above-mentioned Code First Example, we have two entities (Category and Product) we used the proper convention for primary keys for both of these entities, namely CategoryId and ProductId.
However, if we used a different name, such as “UniqueCategoryIdentifier” or “UniqueProductIdentifier,” we must specify that this is our primary key column.
21. What Are Entity Framework’s Scalar And Navigation Properties?
Scalar properties contain actual values. A scalar property corresponds to a database field. Navigation properties allow you to navigate from one entity to another.
22. Is Entity Framework A Free And Open Source Project?
Yeah, of course, Entity Framework (EF) is an ADO.NET object-relational mapping (ORM) framework that is open source. It was previously included in the .NET Framework, but as of Entity Framework version 6, it has been separated from the.NET Framework.
23. How Can We Use Entity Framework Classes To Read Records?
To browse through records, create an object of the context class, and get them from within the context class.
For example, in the code snippet, we are looping through a customer object collection. The context class CustomermytextEntities produces this customer collection. obj = new CustomermytestEntities(); foreach (Customer object in obj.Customers)
24. What Do The CSDL, SSDL, And MSL Sections Of An EDMX File Mean?
It is a component of the EDMX file that aids in database interaction.
CSDL (Conceptual Schema Definition Language): It contains the conceptual abstraction of your database tables that will interact with the user; it aids in creating endpoints with which the user will interact.
SSDL (Storage Schema Definition Language): It is defined as a data structure abstraction because it is the first door through which the database interacts to pass the schema from the database.
MSL (Mapping Schema Language): This language creates a link between the CSDL and the SSDL.
25. In Entity Framework Concurrency, What Is The Client Wins And Store Wins Mode?
Client and Store wins are the actions taken when concurrency occurs. Data is loaded into entity objects in store wins, and data is stored in the database from the client side in client wins.
The 25 Entity Framework interview questions listed above were compiled to assist new and experienced developers looking for a new job or a job change that requires Entity Framework technical skills. I hope you find this Entity Framework synopsis useful.