Don’t use Dependency Injection for your DbContext Instances DbContext controls its lifespan after your data access request is complete, DbContext will automatically close the database connection for you. Although the DbContext implements IDisposable, it should not be manually disposed of or wrapped in a using statement. It would help if you did not dispose of DbContext objects in most cases. If you need multiple database connections or have multiple active contexts operating in parallel, then use the DbContextFactory class instead. The DbContext is a singleton class that represents the gateway to all data access, and therefore should not be instantiated more than once. There Should be Only one DbContext Instance per Request/Unit of Work/Transaction Querying for entity types using LINQ syntax.Managing transactions with the database (including setting up new ones, rolling back existing ones, or even canceling them).It’s one of the core objects in Entity Framework Core, and it has a lot of responsibilities to manage. The DbContext is not just another object.
#Ef does not execute delete command code#
It allows us to write strongly-typed code against our database without having to deal with low-level SQL statements or having to worry about manually mapping classes to database tables. It is one of the fundamental building blocks in the Entity Framework and Entity Framework Core that are used for creating, querying, and updating data from a database.Ī DbContext represents a collection of entity sets or tables in your database. The concept of a DbContext has been around since the first version of the Entity Framework was released. We’ll use this class to perform CRUD operations in the subsequent sections of this article. Protected override void OnModelCreating(ModelBuilder modelBuilder) Protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) Next, create a custom DbContext class named MyDbContext in a file having the same name with a “.cs” extension and replace the default generated code with the code listing given below: public class MyDbContext : DbContext It can be installed either from the NuGet Package Manager tool within Visual Studio or from the NuGet Package Manager console by using the following command: PM> Install-Package NET Core Console Application project and include the NuGet Package onto it. If you don’t have the Northwind database available, you can get the script(s) from here. For the sake of simplicity, instead of creating our own database, we will use the Northwind database. Getting Startedįirst off, we need to have a database against which the queries will be executed. We’ll use a PostgreSQL database using Devart for PostgreSQL to store and retrieve data. This article talks about Db Context concepts and the best practices you can adhere to for improving the performance and scalability of your applications built using ASP.NET 6. This abstraction helps you keep your models independent from EF Core and lets you easily switch persistence providers if needed. It provides an abstraction layer between the domain model and EF Core. The DbContext, the central object in Entity Framework Core, is a gateway to your database. It takes care of performing CRUD operations against your database. In Entity Framework Core (also called EF Core), a Db context is an object that coordinates queries, updates, and deletes against your database. The following example demonstrates the different ways of deleting an entity in the disconnected scenario.Entity Framework Core is an open-source, popular, lightweight, and flexible cross-platform ORM. Attaches the specified entity to the DbContext with Deleted state and starts tracking it.Īttaches a collection or array of entities to the DbContext with Deleted state and starts tracking them.
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