For Books Of March

Time Limited Offer

Exp: 25 Dec, 2019

Introduction to Entity Framework

While the EF Core is relatively new and not as fully developed as the EF 6, it still supports its predecessor’s features and concepts. The EF 6.x is a stable and fully tested ORM technology in many .NET Framework applications. Entity Framework Core is the new and improved version of the Entity Framework for .NET Core applications. EF API infers INSERT, UPDATE, and DELETE commands based on the state of entities when the SaveChanges() method is called.

  • This list is created based on the most notable features and also from frequently asked questions about Entity Framework.
  • This means that in our data model, the two entities will naturally be related to each other.
  • In the following image, an example to adapt to the real development environment is depicted.

It comes at the cost of another abstraction layer, but it will make the code easier to write. EF Core supports two development approaches 1) Code-First 2) Database-First. EF Core mainly targets the code-first approach and provides little support for the database-first approach because the visual designer or wizard for DB model is not supported as of EF Core.

Tools and Extensions – Entity Framework Core

In this case, the CostoStandard column is not a valid field and in fact, is not present in the database. In this case, you will notice an additional class constructor, which initializes the property defined as ICollection on the basis of the HashSet class, that performs operations on the list. In fact, there what is entity framework is not much difference compared to that generated in Database-First, except for some indications, specified in brackets, preceding the various fields. It is called DataAnnotations, elements very useful and concise that allow great flexibility in declaring particular aspects of the data that we will create.

As a developer, we mostly work with data-driven applications, and the ORM Framework generates the necessary SQL (to perform the CRUD operation) that the underlying database can understand. So, in simple words, we can say that the ORM Framework eliminates the need for most of the data access code that, as a developer, we generally write. The term ORM stands for Object-Relational Mapper, and it automatically creates classes based on database tables and vice versa is also true. It can also generate the necessary SQL to create the database based on the classes. In this first part, we have scratched the surface of the entity framework, tried to figure out what it is, how it can come to our aid and what are the paradigms used in its use.

Referencing Entity Framework into projects

We will also see how to carry out an initial database connection and modeling classes, following the two paradigms mentioned above. This model is best suitable for new projects where the database does not exist. This model is stored using the EDMX file and can be viewed and edited by the developer.

what is entity framework

Change the Model Namespace to “EmployeeModel” and click on the “Finish” button as shown in the below image. Once the database is ready, in the next step, create a new “Console Application” with the name EFDemo as shown in the below image. We want to display the data from both tables (Departments and Employees) in a console application as shown below. Learn Entity Framework using simple yet practical examples on EntityFrameworkTutorial.net for free. While using this site, you agree to have read and accepted our terms
of use and privacy policy. The version 4.3.1 was released on February 29, 2012.[10] There were a few updates, like support for migration.

POCO Entities (Plain Old CLR Objects)

This is not a mandatory instruction, but at the same time may be needed to model more accurately our entities. Before you see a couple of examples of the use of EF, you must reference it in our project, i.e, making libraries accessible to the solution. Then we will create a new project in Visual Studio, choose the template that is required (in the example, as anticipated, will sort C # WinForms). Subsequently, save the solution (important to avoid alerts being added EF) and then we open manage Nuget packages.

what is entity framework

This means that in our data model, the two entities will naturally be related to each other. In this case, if for example, we want to re-run the query first, item description and description of the family, we will not directly instruct the compiler on how the tables are related, but we can refer to the property arranged by EF. If we had taken account of this constraint in the design phase, by inserting the Foreign Keys where appropriate, EF would notice it and would be going to create this kind of report automatically. Then we perform a variation on the database structure to see how this affects things in modeling classes. Following the Database-First paradigm, we have already mentioned how the database will provide the framework modeling classes and not vice versa. The Object Services layer includes the Object Context, representing the interaction session between the applications and the data source.

Schema definition language

Developers can work with data in domain-specific objects and properties, such as customers and customer addresses, without worrying about the underlying database tables and columns where this data is kept, courtesy of the Entity Framework. Developers may work with data in domain-specific objects and properties, such as customers and customer addresses, without worrying about the underlying database tables and columns where this data is kept, courtesy of the Entity Framework. The C# Entity Framework is a set of ADO.NET technologies that aid in developing data-driven software. C# Entity framework is an Object Relational Mapping (ORM) framework that gives developers an automated way to store and access databases.

what is entity framework

This approach is an alternative for the code-first approach and the model-first approach. It creates the model and codes from the database in the project and connects them with the database and developer. Either way, Entity Framework works out how to move from your conceptual model to your database. So, you can query against your conceptual model objects and work directly with them.

Features of Entity Framework

It uses a command tree to translate standard SQL languages like LINQ into native SQL expressions, which it then executes on the given DBMS system. Entity Framework is an ORM and ORMs are aimed to increase the developer’s productivity by reducing the redundant task of persisting the data used in the applications. The EF Core supports relational and non-relational databases, which is possible due to the database providers. The Database Provider sits between the EF Core and the Database it supports.

There are other ORMs in the marketplace such as NHibernate and LLBLGen Pro. But Entity Framework can do all of the above automatically for us if we provide the necessary database schema to the Entity Framework. Let us understand this step by step how to achieve the same using Entity Framework. Suppose we want to develop an application to manage the students of a college. To do this, we may need to create classes such as Student, Department, Address, etc. Technically, we called these classes Domain classes or business objects.

Native SQL

It eliminates the need for accessing the code of the data that developers need to write. To properly use the source, code must be changed the instance of SQL Server access, as specified in the App.config file of the project, and in that instance you will have to create a name for TECHNET database. In our case, we select the two tables created, leaving the rest of the settings as proposed. We are now ready to use the potential of our ORM, as far as development is concerned.

Leave a Reply

Your email address will not be published. Required fields are marked *

Main Menu