本文共 2359 字，大约阅读时间需要 7 分钟。
数据库管理软件是MS SQL，数据库是微软的NorthWind。
主体代码,完整的解决方案见最下方
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 6 namespace TestCodeFirst 7 { 8 class Program 9 {10 static void Main(string[] args)11 {12 ValidaProduct();13 UpdateProduct();14 GetSpecialProduct();15 }16 17 private static void ValidaProduct()18 {19 using (Northwind northwind = new Northwind())20 {21 var product = northwind.Products.Find(1);22 Console.WriteLine(string.Format("product.Name{0} product.UnitPrice:{1}", product.ProductName, product.UnitPrice));23 product.ProductName = null;24 product.UnitPrice = 2.33M;25 product.Discontinued = false;26 northwind.SaveChanges();27 }28 }29 30 private static void UpdateProduct()31 {32 using (Northwind northwind = new Northwind())33 {34 var product = northwind.Products.Find(1);35 Console.WriteLine(string.Format("product.Name{0} product.UnitPrice:{1}",product.ProductName, product.UnitPrice));36 product.UnitPrice = 2.33M;37 product.Discontinued = false;38 northwind.SaveChanges();39 40 var product2 = northwind.Products.Find(1);41 Console.WriteLine(string.Format("product.Name{0} product.UnitPrice:{1}", product.ProductName, product2.UnitPrice));42 }43 }44 45 private static void GetSpecialProduct()46 {47 using (Northwind northwind = new Northwind())48 {49 var product = from p in northwind.Products50 where p.Category.CategoryName == "Beverages"51 select p;52 foreach (var item in product)53 {54 Console.WriteLine(string.Format("ProductName:{0}", item.ProductName));55 }56 Console.WriteLine(string.Format("执行结果：{0}", product == null));57 }58 }59 }60 } 转载：http://www.cnblogs.com/kissazi2/archive/2013/01/04/2843974.html