public static void EnsureSeedDataForContext(this MyContext context) { if (context.Products.Any()) { return; } var products = new List <Product> { new Product { Name = "牛奶", Price = new decimal(2.5), Description = "这是牛奶啊", Materials = new List <Material> { new Material { Name = "水" }, new Material { Name = "奶粉" } } }, new Product { Name = "面包", Price = new decimal(4.5), Description = "这是面包啊", Materials = new List <Material> { new Material { Name = "面粉" }, new Material { Name = "糖" } } }, new Product { Name = "啤酒", Price = new decimal(7.5), Description = "这是啤酒啊", Materials = new List <Material> { new Material { Name = "麦芽" }, new Material { Name = "地下水" } } } }; context.Products.AddRange(products); context.SaveChanges(); }