Context

Rahman Niftaliyev

The SampleDbContext class context defines a model for authors and books. It also defines a HasMany relationship between the Author entity and the Books entity. The SampleDbContext class also defines a HasOne relationship between the Author entity and the Book entity. Finally, the SampleDbContext class defines a ForeignKey relationship between the AuthorId column in the Author entity and the AuthorId column in the Books entity.

using System;
using System.Linq;
using EasyRepository.Sample.Entities;
using System.Collections.Generic;
using Microsoft.EntityFrameworkCore;
using System.Threading.Tasks;



namespace EasyRepository.Sample.Context
{
  /// <summary>
  /// Sample Database Context
  /// </summary>
  public class SampleDbContext : DbContext
  {
    /// <summary>
    /// Ctor
    /// </summary>
    /// <param name="options">
    /// The options to be used by a Microsoft.EntityFrameworkCore.DbContext. You normally
    ///     override Microsoft.EntityFrameworkCore.DbContext.OnConfiguring(Microsoft.EntityFrameworkCore.DbContextOptionsBuilder)
    ///     or use a Microsoft.EntityFrameworkCore.DbContextOptionsBuilder to create instances
    ///     of this class and it is not designed to be directly constructed in your application
    ///     code.
    /// </param>
    public SampleDbContext(DbContextOptions options) : base(options)
    {
    }

    protected SampleDbContext()
    {
    }

    public virtual DbSet<Author> Authors { get; set;}

    public virtual DbSet<Book> Books { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
      base.OnModelCreating(modelBuilder);
      modelBuilder.Entity<Author>(entity =>
      {
        entity
          .HasMany(m => m.Books)
          .WithOne(o => o.Author)
          .HasForeignKey(fk => fk.AuthorId);
      });

      modelBuilder.Entity<Book>(entity =>
      {
        entity
          .HasOne(o => o.Author)
          .WithMany(m => m.Books)
          .HasForeignKey(fk => fk.AuthorId);
      });
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
      base.OnConfiguring(optionsBuilder);
    }
  }
}