Challenge #1 - Expression - Manual

ProductsController.cs

// x =>
var parameter = Expression.Parameter(typeof(Product), "x"); 

// x => x.Code
var property = Expression.Property(parameter, "Code");

// x.Code == filter.Code
var comparison = Expression.Equal(property, Expression.Constant(filter.Code));

var lambda = Expression.Lambda<Func<Product, bool>>(comparison, parameter);
var query = db.Products.Where(comparison);