Category Archives: IT Education

Introduction to Entity Framework

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. Entity Framework Core uses a provider model to access many different databases. EF Core includes providers as NuGet packages which you need to install. Entity Framework Core is the new version of Entity Framework after EF 6.x. It is open-source, lightweight, extensible and a cross-platform version of Entity Framework data access technology.

  • If you’re considering working with a database engine, I highly recommend looking at EF Core as an option to jumpstart your development.
  • Each record’s type is distinguished by a Discriminator column, which usually holds a simplified C# type name.
  • Below I’ll share a code example that shows how you can execute queries asynchronously in EF Core.
  • This approach is an alternative for the code-first approach and the model-first approach.

A third version of Entity Framework, version 4.1, was released on April 12, 2011, with Code First support. By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. In code, you might want to work with objects in an object oriented fashion. This tutorial is designed for those who want to learn how to start the development of the Entity Framework in their application.

Basic Workflow in Entity Framework

EF simplifies mapping between objects in your software to the tables and columns of a relational database. In this article we examined 10 key strategies you can use to improve data access performance in EF Core. Additionally, you should fine-tune your database design, indexes, queries, and stored procedures to get maximum benefits. It is imperative that you keep performance in mind from the outset what is entity framework whenever you are building applications that use a lot of data. You can improve data access performance in EF Core in many different ways, ranging from using eager loading to reducing the database round trips required by your queries. In this article, we will explore 10 tips and tricks or strategies we can use in EF Core to improve the data access performance of our .NET Core applications.

Assume we have the following 2 tables (Departments and Employees). I updated the connection string in my web.config file located in the root directory of the web application. The following code snippet shows how you can use IQueryable to query data. The following code snippet shows how to obtain data in a paged fashion. Notice how the beginning page index and page size have been used to choose just the required data. The EF Core database provider usually contains the functionality specific to the database it supports.

What is an Entity in Entity Framework?

As mentioned in the previous section, aggregations are essential for providing summary data. In this example, we’ll look at the sources of ratings and how many exist in our database. Aggregation is one of the most important reasons to use a relational database, and with LINQ, using an aggregate function like Sum, Average, and Max is straightforward. Let’s find the highest-rated production by averaging the Star value on a Rating.

what is entity framework

By eliminating the need to load unnecessary related entities (as in explicit loading), lazy loading seems to relieve the developer from dealing with related entities entirely. Because EF Core is adept at automatically loading related entities from the database when accessed by your code, lazy loading seems like a nice feature. The code snippet given below shows how you can retrieve entities directly from the database for read-only purposes, without tracking and without loading them into the memory. The EF Core supports relational and non-relational databases, which is possible due to database providers. The Database Provider sits between the EF Core and the database it supports.

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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. Learn Entity Framework using simple yet practical examples on for free. Learn Entity Framework DB-First, Code-First and EF Core step by step.

what is entity framework

Despite these updates, the EDMX model seems to be linked to the previous database schema. I have a new column in a table of the new DB, although the table already exists in the old DB the new column doesn’t, so when I refresh I’m not able to see the new column in the diagram. Finally, every application has different data access requirements and characteristics. You should benchmark your EF Core performance before and after you apply any of the changes we discussed here to assess the results for your specific application.

what is entity framework

Because DbContext objects may be costly to create and dispose of, EF Core offers a mechanism for pooling them. By pooling, DbContext objects are created once, then reused when needed. For read-only queries, i.e., when you want to retrieve entities without modifying them, you should use AsNoTracking to improve performance. The following code snippet illustrates how AsNoTracking can be used to disable tracking for an individual query in EF Core.

Up to this point, we should have a schema expressed through the EntertainmentDbContext that we can apply to a database, although we’ve yet to apply any changes to our database. In our case, we are using an SQLite database so that folks can get up and running quickly with few external dependencies. From the Terminal tool window in JetBrains Rider, let’s run the following command.