fluent api many to many ef core code example

Example 1: many to many ef core

protected override void OnModelCreating(ModelBuilder modelBuilder){    modelBuilder.Entity<BookCategory>()        .HasKey(bc => new { bc.BookId, bc.CategoryId });      modelBuilder.Entity<BookCategory>()        .HasOne(bc => bc.Book)        .WithMany(b => b.BookCategories)        .HasForeignKey(bc => bc.BookId);      modelBuilder.Entity<BookCategory>()        .HasOne(bc => bc.Category)        .WithMany(c => c.BookCategories)        .HasForeignKey(bc => bc.CategoryId);}

Example 2: one to many relationship ef core

// 1:M
// ONE company has MANY employees

public class Company
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<Employee> Employees { get; set; }
}
public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Company Company { get; set; }
}