本人搭建Test环境的目的是测试N+1查询和LazyLoading，参考书籍：你必须掌握的Entity Framework 6.x与Core 2.0， 工具：VS2019

1. 创建Console application
2. Add entityframework
3. Add class and context class

    class Program
    {
        static void Main(string[] args)
        {
            using (var test = new TestContext())
            {
                Database.SetInitializer(new DropCreateDatabaseAlways<TestContext>());
            test.Owners.Add(new Owner()
            {
                Name = "owner1",
                Cats = new List<Cat>
                {
                    new Cat()
                    {
                        Name = "Cat1",
                        Age = 1,
                        BirthTime = DateTime.Now,
                        Color = "Red"
                    },
                    new Cat()
                    {
                        Name = "Cat2",
                        Age = 2,
                        BirthTime = DateTime.Now,
                        Color = "Yellow"
                    }
                }
            });

            test.Owners.Add(new Owner()
            {
                Name = "owner11",
                Cats = new List<Cat>
                {
                    new Cat()
                    {
                        Name = "Cat11",
                        Age = 1,
                        BirthTime = DateTime.Now,
                        Color = "Green"
                    }
                }
            });

            test.Owners.Add(new Owner()
            {
                Name = "owner2",
                Cats = new List<Cat>
                {
                    new Cat()
                    {
                        Name = "Cat3",
                        Age = 1,
                        BirthTime = DateTime.Now,
                        Color = "Green"
                    },
                    new Cat()
                    {
                        Name = "Cat4",
                        Age = 2,
                        BirthTime = DateTime.Now,
                        Color = "Blue"
                    }
                }
            });


                test.SaveChanges();
            }
        }
    }

    public class Cat
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public int Age { get; set; }
        public DateTime BirthTime { get; set; }
        public string Color { get; set; }
        public int OwnerId { get; set; }
    }

    public class Owner
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public ICollection<Cat> Cats { get; set; }
    }


    public class TestContext : DbContext
    {
        public DbSet<Cat> Cats { get; set; }
        public DbSet<Owner> Owners { get; set; }
    }

1. 通过代码添加测试数据，删除代码后，进行其他测试
2. Database.SetInitializer(new DropCreateDatabaseAlways<TestContext>()); 每次运行代码都会重新生成数据库
3. 不设置connectionstring的情况下，数据库生成在VS安装自带的SqlServer实例，版本为Microsoft SQL Server Express Edition。

4. 可通过VS的SQL Server Object Explorer查看数据库

   
   
   image.png
   
   

   生成数据库名字：console application name + context name