DB Context & DB Set

Description

• The DbContext class is an integral part of Entity Framework.
• An instance of DbContext represents a session with the database which can be used to query and save instances of your entities to a database.

• DbContext in EF Core allows us to perform the following tasks:

  • Manage database connection
  • Configure model & relationship
  • Querying database
  • Saving data to the database
  • Configure change tracking
  • Caching
  • Transaction management

Syntax

public class ApplicationDbContext : DbContext {
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options) {
    }
}

• It should inherit from DbContext
• It should be a public class

Connecting to Project

For EF inside our project, we should add it into the project services by the below code

builder.Services.AddDbContext<ApplicationDbContext>(option => {
    option.UseSqlServer(builder.Configuration.GetConnectionString("DefaultSQLConnection"));
});

• The GetConnectionString method will read the below part of the appsettings.json file

  "ConnectionStrings": {
      "DefaultSQLConnection": "Server=.;Database=Magic_VillaAPI;TrustServerCertificate=True;"
  },
  

DB Set

Is a property inside the DbContext that will make one model accessible from the DbContext

public DbSet<Category> Categories { get; set; }