Entity Framework Core - Soft delete

The easiest way to implement soft delete in EF Core is through query filters.

This filter can be specified when creating our EF Core model:

	protected override void OnModelCreating(ModelBuilder builder)
	{
	base.OnModelCreating(builder);
	builder.Entity<Role>().Property<bool>("isDeleted");
	builder.Entity<Role>().HasQueryFilter(r => EF.Property<bool>(r, "isDeleted") == false);
	}

view raw QueryFilter.cs hosted with ❤ by GitHub

Now every time when query for the ‘Role’ object an extra ‘WHERE’ clause is included that filters with IsDeleted=false.

But hold your horses we are not there yet, we also have to override our SaveChanges()and SaveChangesAsyc() methods on the DbContext otherwise the ‘Role’ entity will still be removed from the database when we call Remove().

	public override int SaveChanges()
	{
	SoftDelete();
	return base.SaveChanges();
	}
	public override Task SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = default(CancellationToken))
	{
	SoftDelete();
	return base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
	}
	private void SoftDelete()
	{
	var markedAsDeleted = ChangeTracker.Entries().Where(x => x.State == EntityState.Deleted);
	foreach (var item in markedAsDeleted)
	{
	//TODO: Create a more generic alternative
	if (item.Entity is Role role)
	{
	item.State = EntityState.Unchanged;
	role.IsDeleted = true;
	}
	}
	return base.SaveChanges();
	}

view raw SaveChanges.cs hosted with ❤ by GitHub

Remark: As a possible improvement you could generate a base class or interface for all ‘soft deletable’ entities.