#3 Добавил сущность отзыва от пользователя.

PhoneStore/Migrations/20220807164848_AddFeedbackEntity.cs

+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+namespace PhoneStore.Migrations
+{
+    public partial class AddFeedbackEntity : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "Feedbacks",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "integer", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    UserId = table.Column<int>(type: "integer", nullable: false),
+                    PhoneId = table.Column<int>(type: "integer", nullable: false),
+                    Text = table.Column<string>(type: "text", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Feedbacks", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Feedbacks_AspNetUsers_UserId",
+                        column: x => x.UserId,
+                        principalTable: "AspNetUsers",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_Feedbacks_Phones_PhoneId",
+                        column: x => x.PhoneId,
+                        principalTable: "Phones",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Feedbacks_PhoneId",
+                table: "Feedbacks",
+                column: "PhoneId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Feedbacks_UserId",
+                table: "Feedbacks",
+                column: "UserId");
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "Feedbacks");
+        }
+    }
+}

PhoneStore/Migrations/MobileContextModelSnapshot.cs

@@ -152,6 +152,31 @@ namespace PhoneStore.Migrations
                     b.ToTable("Brands");
                 });
 
+            modelBuilder.Entity("PhoneStore.Models.Feedback", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasAnnotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn);
+
+                    b.Property<int>("PhoneId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("Text")
+                        .HasColumnType("text");
+
+                    b.Property<int>("UserId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("PhoneId");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("Feedbacks");
+                });
+
             modelBuilder.Entity("PhoneStore.Models.Order", b =>
                 {
                     b.Property<int>("Id")
@@ -366,6 +391,25 @@ namespace PhoneStore.Migrations
                     b.Navigation("Phone");
                 });
 
+            modelBuilder.Entity("PhoneStore.Models.Feedback", b =>
+                {
+                    b.HasOne("PhoneStore.Models.Phone", "Phone")
+                        .WithMany()
+                        .HasForeignKey("PhoneId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneStore.Models.User", "User")
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Phone");
+
+                    b.Navigation("User");
+                });
+
             modelBuilder.Entity("PhoneStore.Models.Order", b =>
                 {
                     b.HasOne("PhoneStore.Models.Phone", "Phone")

PhoneStore/Models/Feedback.cs

+namespace PhoneStore.Models
+{
+    public class Feedback
+    {
+        public int Id { get; set; }
+        public int UserId { get; set; }
+        public int PhoneId { get; set; }
+        public string Text { get; set; }
+        public User User { get; set; }
+        public Phone Phone { get; set; }
+    }
+}
\ No newline at end of file

PhoneStore/Models/MobileContext.cs

@@ -9,6 +9,7 @@ namespace PhoneStore.Models
         public DbSet<Order> Orders { get; set; }
         public DbSet<Basket> Baskets { get; set; }
         public DbSet<Brand> Brands { get; set; }
+        public DbSet<Feedback> Feedbacks { get; set; }
 
         public MobileContext(DbContextOptions<MobileContext> options) : base(options)
         {