Expanded basic sample

samples/BasicSample/Program.cs

@@ -2,27 +2,60 @@
 using EntityFrameworkCore.Projections.Extensions;
 using Microsoft.Data.Sqlite;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.DependencyInjection;
 using System;
+using System.Collections;
+using System.Collections.Generic;
 using System.Linq;
 
 namespace BasicSample
 {
-    public partial class User
+    public class User
     {
         public int Id { get; set; }
-
         public string FirstName { get; set; }
-
         public string LastName { get; set; }
 
+        public ICollection<Order> Orders { get; set; }
+
         [Projectable]
         public string FullName
-            => FirstName + " " + LastName;
+            => $"{FirstName} {LastName}";
 
         [Projectable]
-        public string FullNameFunc()
-            => FirstName + " " + LastName;
+        public double TotalSpent => Orders.Sum(x => x.PriceSum);
+    }
+
+    public class Product
+    {
+        public int Id { get; set; }
+        public string Name { get; set; }
+        public double Price { get; set; }
+    }
+
+    public class Order
+    {
+        public int OrderId { get; set; }
+        public int ProductId { get; set; }
+        public ICollection<OrderItem> Items { get; set; }
+
+        [Projectable]
+        public double PriceSum => Items.Sum(x => x.TotalPrice);
+    }
+
+    public class OrderItem
+    {
+        public int OrderId { get; set; }
+        public int ProductId { get; set; }
+        public int Quantity { get; set; }
+        public double UnitPrice { get; set; }
+
+        public Order Order { get; set; }
+        public Product Product { get; set; }
+
+        [Projectable]
+        public double TotalPrice => Quantity * UnitPrice;
     }
 
     public class ApplicationDbContext : DbContext
@@ -31,6 +64,11 @@ namespace BasicSample
         {
         }
 
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<OrderItem>().HasKey(x => new { x.OrderId, x.ProductId });
+        }
+
         public DbSet<User> Users { get; set; }
     }
 
@@ -53,7 +91,29 @@ namespace BasicSample
             var dbContext = serviceProvider.GetRequiredService<ApplicationDbContext>();
             dbContext.Database.EnsureCreated();
 
-            var user = new User { FirstName = "Jon", LastName = "Doe" };
+            var product1 = new Product { Name = "Red pen", Price = 1.5 };
+            var product2 = new Product { Name = "Blue pen", Price = 2.1 };
+
+            var user = new User { 
+                FirstName = "Jon", 
+                LastName = "Doe", 
+                Orders = new List<Order> {
+                    new Order {
+                        Items = new List<OrderItem> {
+                            new OrderItem {
+                                Product = product1,
+                                UnitPrice = product1.Price,
+                                Quantity = 1
+                            },
+                            new OrderItem {
+                                Product = product2,
+                                UnitPrice = product2.Price,
+                                Quantity = 2
+                            }
+                        }
+                    }
+                }
+            };
 
             dbContext.Users.Add(user);
 
@@ -61,9 +121,10 @@ namespace BasicSample
 
             var query = dbContext.Users
                 .Select(x => new {
-                     Foo = x.FullNameFunc()
+                     Name = x.FullName,
+                     x.TotalSpent
                  });
-
+            
             Console.WriteLine(query.ToQueryString());
 
             var r1 = query.ToArray();