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

namespace SQL_LINQ
{
    class linq_To_SqlServer
    {
        //查詢
        public void Select()
        {
            DataTestDataContext dc = new DataTestDataContext(); //建立物件
            var user = from u in dc.User orderby u.U_Id descending select u;    //查詢語句
            Console.WriteLine("按照ID倒序排列:");
            foreach (var item in user)
            {
                Console.WriteLine(item.U_Name);
            }
        }

        //插入
        public void Insert()
        {
            User user = new User { U_Name = "毛八", U_Pwd = "3" };    //插入資料
            DataTestDataContext dc = new DataTestDataContext(); //建立物件
            dc.User.InsertOnSubmit(user);   //執行插入操作
            dc.SubmitChanges(); //執行更新
        }

        //更新
        public void Update()
        {
            DataTestDataContext dc = new DataTestDataContext(); //建立物件
            var user = from u in dc.User where u.U_Id == 1 select u;    //找到要修改的資料
            foreach (var item in user)
            {
                item.U_Name = "張三";
                item.U_Pwd = "000";
            }
            dc.SubmitChanges(); //執行更新
        }

        //刪除
        public void Delete()
        {
            DataTestDataContext dc = new DataTestDataContext(); //建立物件
            var user = from u in dc.User where u.U_Id == 2 select u;    //找到要刪除的資料
            foreach (var item in user)
            {
                dc.User.DeleteOnSubmit(item);   //刪除操作
            }
            dc.SubmitChanges(); //執行更新
        }
    }
}
 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using SQL_LINQ;
using System.Data.SqlClient;

namespace SQL_LINQ
{
    class Program
    {
        static void Main(string[] args)
        {

            //LinqToSql
            #region
            linq_To_SqlServer LTS = new linq_To_SqlServer();

            //LTS.Select(); //查詢函式

            //LTS.Insert();   //插入函式

            //LTS.Update();   //更新函式

            //LTS.Delete();   //刪除函式
            #endregion
            Console.ReadLine();

        }
    }
}