Entity Framework Classic ThenInclude

Description

You can chain multiple related objects to the query result by using the AlsoInclude and ThenInclude methods. The ThenInclude method moves the chaining level to the property included. It allows to include related objects from the next level.

ThenInclude is a syntactic sugar method to make it easier and clearer to include multiple related objects.

ctx.Customers
	.Include(customer => customer.Orders)
		.ThenInclude(order => order.OrderDetails)
		.ThenInclude(orderDetail => orderDetail.Product)
	.ToList();

Try it: NET Framework | NET Core

ctx.Customers
	.Include(customer => customer.Orders)
		.ThenInclude(order => order.OrderDetails.Select(orderDetail => orderDetail.Product))
	.ToList();

Try it: NET Framework | NET Core

ctx.OrderDetails
	.Include(orderDetail => orderDetail.Product)
		.ThenInclude(product => product.Category)
	.Include(orderDetail => orderDetail.Product)
		.ThenInclude(product => product.Supplier)
	.ToList();

Try it: NET Framework | NET Core

Note

  • If you want to reset the level to the root, use Include
  • If you want to include items from the same level, use AlsoInclude

Limitations

DbQuery

Chaining includes only work if the first include call is from a DbQuery. If you used some LINQ and the query is currently an IQueryable, you can use the method AsDbQuery to tell the compiler that's a DbQuery. This restriction is currently required to avoid some side impact with queries that are not directly using DbQuery class.

ctx.OrderDetails
	.Where(orderDetail => orderDetail.Quantity > 1)
	.AsDbQuery()
	.Include(orderDetail => orderDetail.Product)
		.ThenInclude(product => product.Category)
	.Include(orderDetail => orderDetail.Product)
		.ThenInclude(product => product.Supplier)
	.ToList();

Try it: NET Framework | NET Core

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