EF Core Triggers Use Triggers

To use triggers on your entities, the simple way is to inherit your context class from DbContextWithTriggers.

So first, we need to update our context class by inheriting it from the DbContextWithTriggers class, as shown below.

using EFTriggersDemo.Models;
using EntityFrameworkCore.Triggers;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace EFTriggersDemo.DAL
{
    public class BookStore : DbContextWithTriggers
    {
        public BookStore(DbContextOptions<BookStore> options) : base(options)
        {
        }
        public DbSet<Author> Authors { get; set; }
        public DbSet<Book> Books { get; set; }
    }
}

Let's define an abstract class that contains two properties, and we will also enable automatic insert and update stamps for any entity that inherits this class.

using EntityFrameworkCore.Triggers;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace EFTriggersDemo.Models
{
	public abstract class Trackable
	{
		public DateTime Inserted { get; private set; }
		public DateTime Updated { get; private set; }

		static Trackable()
		{
			Triggers<Trackable>.Inserting += entry => entry.Entity.Inserted = entry.Entity.Updated = DateTime.UtcNow;
			Triggers<Trackable>.Updating += entry => entry.Entity.Updated = DateTime.UtcNow;
		}
	}
}

Events are raised from the base class, up to the events specified on the entity class being used. Now we will update the Author class by inheriting it from the Trackable class.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace EFTriggersDemo.Models
{
    public class Author : Trackable
    {
        public int AuthorId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public DateTime BirthDate { get; set; }
        public virtual ICollection<Book> Books { get; set; }
    }
}

Now execute your application again and open the Authors table.