Руководство по Entity Framework Core 8 и C#

Here, I briefly introduced Entity Framework Core in this article, and I hope you enjoy this Introduction to Entity Framework Core article. This is the first article of the Entity Framework Core article series, and in this article, I will give you an overview of Entity Framework Core. The Entity Framework Core, or EF Core, is the latest version of Entity Framework and completely rewrites from the ground up. This figure shows where the Entity Framework fits in the application. Entity Framework tutorial provides basic and advanced concepts of Entity Framework. Our Entity Framework tutorial is designed for beginners and professionals.

The version 4.3.1 was released on February 29, 2012.[10] There were a few updates, like support for migration. Entity Framework Core is the new and improved version of Entity Framework for .NET Core applications. However, it can also be used with standard .NET 4.5+ framework based applications.

Step 4: Create the DbContext

There are other ORMs in the marketplace, such as NHibernate and LLBL Gen Pro. Most ORMs typically map the type of the domain directly to the schema of the database. EF Core continues to support the following features and concepts, same as EF 6. It is an enhancement to ADO.NET that gives developers an automated mechanism for accessing & storing the data in the database. Entity Framework Core (EF Core) is an ORM (Object-Relational Mapping) framework for the .NET platform. In order to fully take advantage of this Entity Framework Course, you should have basic knowledge of C# and any database such as SQL Server, Oracle, or MySQL to learn more about these tutorials.

It provides a connection between the business entity and data tables in the database. It saves data stored in the properties of business entities and also retrieves data from the database and converts it to business entities objects automatically. Entity Framework will execute the relevant query in the database and then materialize results into instances of your domain objects for you to work within your app. That means the Entity Framework eliminates the need to write the data-access code that developers usually need to write. Now your object directly works with the database to retrieve or make changes.

ASP.NET Core Online Training Program

Entity Framework (EF) is an open source[2] object–relational mapping (ORM) framework for ADO.NET. It was originally shipped as an integral part of .NET Framework, however starting with Entity Framework version 6.0 it has been delivered separately from the .NET Framework. In this step-by-step guide, we’ll walk you through the process of installing and implementing Entity Framework in a .NET Core application. We’ll also use SQL Server as the database and show you how to install the required NuGet package, EntityFrameworkCore.SqlServer. Entity Framework (EF) is a powerful and widely used Object-Relational Mapping (ORM) tool for .NET Core developers.

This Entity Framework Course is designed for Students, Beginners, Intermediates, and Professionals Developers who want to learn Entity Frameworks step by step, from the basics to the advanced concepts. This tutorial provides a hands-on approach to the subject with step-by-step program examples that will assist you in learning and putting the acquired knowledge into practice. 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. Let us understand why we need to use the ORM Framework with an example.

Querying data

Entity Framework is an open-source ORM (Object Relational Mapping) Framework for the .NET applications supported by Microsoft. It enables the developers to work with the data using the objects of domain-specific classes without focussing on the database tables and columns where the data is stored. With the Entity Framework, developers can work at a higher level of abstraction when developers deal with the data. With the help of Entity Framework, we can create and maintain data-oriented applications with less code when compared with traditional applications. The above figure represents how an entity framework interacts with the domain class and database.

This will increase the overall amount of time required to complete an application. If you have an existing database and database tables are already there, you must use the EF Core Database First Approach. In the database-first approach, the EF Core creates the DBContext and Domain Classes based on the existing database schema using EF Core Command. 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. EF Core supports two development approaches 1) Code-First 2) Database-First.

Schema definition language

The following figure illustrates where the Entity Framework fits into your application. Various profilers are commercially available to troubleshoot performance issues using Entity Framework, both for EF and EF Core variants.

Then, we create DataSet or DataTables to store the data in memory and perform different types of operations on the data as per the business requirements. Then, based on the application domain classes and DBContext class, the EF Core creates the database and related tables. For a better understanding, please have a look at the following diagram. 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.

LINQ to Entities

The Entity Framework is an Object/Relational Mapping (O/RM) framework that maps objects to relational databases. EF Core is designed to work with .NET Core applications but can also be used with standard .NET Framework applications based on Framework 4.5 or higher. The following diagram shows the supported types of applications that we can develop using EF Core. As per the above figure, Entity Framework fits between the business entities (domain classes) and the database. In the code-first approach, EF Core API creates the database and tables using migration based on the conventions and configuration provided in your domain classes. This late-bound or «weakly-typed» approach to data access is prone to error.

• It provides a connection between the business entity and data tables in the database.
• Various profilers are commercially available to troubleshoot performance issues using Entity Framework, both for EF and EF Core variants.
• Entity Framework is an open-source ORM (Object Relational Mapping) Framework for the .NET applications supported by Microsoft.
• For this, we need to create a Connection Object with the database, then Open the Connection, Create the Command Object, and execute the Command using Data Reader or Data Adapter.

It was released along with .NET Core and is an Extensible, Lightweight, Open Source, and Cross-Platform Version of Entity Framework data access technology. EF API infers INSERT, UPDATE, and DELETE commands based on the state of entities when the SaveChanges() method is called. The ChangeTrack keeps track of the states of each entity as and when an action is performed. The following figure illustrates the supported application types, .NET Frameworks and OSs. Entity Framework Core is the new version of Entity Framework after EF 6.x.

It provides an abstract level to the developers to work with a relational table and columns by using the domain-specific object. It also reduces the code size of the entity framework meaning data specific applications and also the readability of the code increases by using it. This is a new technology for accessing the data for Microsoft application.