Visual Studio 2008使用LINQ to SQL

首先新建一个Console Application项目：ISPLinqDemo

 

在数据库中新建一个表：tb_Test

---------------------------------------

UserID   | int          | primary key

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UserName | nvarchar(50) |

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然后在资源解决方案中右击添加项"LINQ to SQL Classes"，命名为：TestData

 

然后从Server Explorer中将表tb_Test拖到新建的"LINQ to SQL Classes"。

此时，会自动生成一些相关的变量与操作。比如TestDataDataContext等。

 

代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

 

namespace ISPLinqDemo

{
    class Program
    {
        static void Main(string[] args)
        {
            /*
            // SelectData
            int id = 1;
            IEnumerable tests = LinqOperations.SelectData(id);
            foreach (var test in tests)
            {
                Console.WriteLine("ID: " + test.UserID + "\tName: " + test.UserName);
            }
             */

 

            /*
            //InsertData
            tb_Test testmp = new tb_Test();
            testmp.UserID = 403;
            testmp.UserName = "403";
            if (LinqOperations.InsertData(testmp) == true)
                Console.WriteLine("数据插入成功！");
             */

 

            /*
            // UpdateData
            int updateID = 403;
            tb_Test newTest = new tb_Test();
            newTest.UserName = "ISP";
            if (LinqOperations.UpdateData(newTest, updateID) == true)
                Console.WriteLine("数据更新成功！");
             */

 

            /*
            // DeleteData
            int deleteID = 1;
            if (LinqOperations.DeleteData(deleteID) == true)
                Console.WriteLine("数据删除成功！");
             */

 

            Console.ReadKey();
        }
    }

    class LinqOperations
    {
        private static TestDataDataContext db;

 

        ///

        /// 初始化DataContext
        ///

        ///
        private static void LinqOperationInit()
        {
            if (db == null)
                db = new TestDataDataContext();
        }

 

        ///

        /// 插入数据
        ///

        ///
        /// 插入是否成功
        public static bool InsertData(tb_Test test)
        {
            LinqOperationInit();
            try
            {
                db.tb_Tests.InsertOnSubmit(test);
                db.SubmitChanges();
                return true;
            }
            catch (Exception err)
            {
                Console.WriteLine("数据插入失败：" + err);
                return false;
            }
        }

 

        ///

        /// 筛选数据
        ///

        ///
        /// 筛选指定ID的结果集
        public static IEnumerable SelectData(int ID)
        {
            LinqOperationInit();
            try
            {
                var data = from test in db.tb_Tests
                           where test.UserID == ID
                           select test;
                return data;
            }
            catch (Exception err)
            {
                Console.WriteLine("数据查询失败：" + err);
                return null;
            }
        }

 

        ///

        /// 更新数据
        ///

        ///
        ///
        /// 更新是否成功
        public static bool UpdateData(tb_Test test, int ID)
        {
            LinqOperationInit();
            try
            {
                var data = from testmp in db.tb_Tests
                           where testmp.UserID == ID
                           select testmp;

                foreach (tb_Test newTest in data)
                {
                    newTest.UserName = test.UserName;
                }

                db.SubmitChanges();
                return true;
            }
            catch (Exception err)
            {
                Console.WriteLine("数据更新失败：" + err);
                return false;
            }
        }

 

        ///

        /// 删除数据
        ///

        ///
        /// 删除是否成功
        public static bool DeleteData(int ID)
        {
            LinqOperationInit();
            try
            {
                var data = from test in db.tb_Tests
                           where test.UserID == ID
                           select test;
                if (data.Count() > 0)
                {
                    db.tb_Tests.DeleteOnSubmit(data.First());
                    db.SubmitChanges();
                    return true;
                }
                else
                {
                    Console.WriteLine("数据删除失败！");
                    return false;
                }
            }
            catch (Exception err)
            {
                Console.WriteLine("数据删除失败：" + err);
                return false;
            }
        }
    }
}