in opbeans-dotnet/Controllers/OrdersController.cs [25:38]
public ActionResult<OrderDetail> Get(int id)
{
var order = _dbDbContext.Orders.First(n => n.Id == id);
return _dbDbContext.OrderLines
.Join(_dbDbContext.Products,
line => line.ProductId,
prod => prod.Id,
(line, prod) => new OrderDetail
{
Id = order.Id, CreatedAt = order.CreatedAt, CustomerId = order.CustomerId,
Lines = Mapper.Map<Product>(prod)
}).First(n => n.Id == order.Id);
}