DbContext

DbContext is a primary class in Entity Framework (EF) that represents a session with a database and provides the API used to query and save instances of entity classes. In EF Core, applications define a derived class from DbContext with a set of properties of type DbSet<TEntity> that expose the entities you want to query or save.

The context tracks changes to retrieved entities via a change tracker, enabling updates, inserts, and deletes to be persisted back to the database when SaveChanges or SaveChangesAsync is called. It also coordinates relationships among entities and performs identity resolution so multiple queries return the same CLR instance for the same row.

Contexts are configured with DbContextOptions, which specify the database provider, connection string, and other behaviors. A context is typically created per unit of work or per request and disposed when the operation completes. It can be used with dependency injection in modern apps.

DbSet properties map to tables; LINQ queries are translated to SQL. EF Core supports features such as change tracking, lazy loading (via proxies), explicit loading, transactions, migrations, and query tracking modes.

As a gateway to data, DbContext is the unit of work and uses DbSet to perform CRUD operations. It relies on conventions, data annotations, and the Fluent API to configure the model. The context plays a central role in the data access layer, coordinating query construction, change tracking, and persistence across the application's data access code.