class Students{[Key]public int stuId { get; set; }public string stuName { get; set; }public string stuAdress { get; set; }public int stuAge { get; set; }}

   class StuDbContext : DbContext{public DbSet<Students> student { get; set; }}

     static void Add(){Students st = new Students { stuAdress = "中关村", stuAge = 20, stuName = "刘德华" };using (StuDbContext db = new StuDbContext()){db.student.Add(st);db.SaveChanges();}}

    static void Main(string[] args){Add();Console.WriteLine("成功");Console.ReadKey();}

  <connectionStrings><add name="stuDb" connectionString="server=.;database=StudentInfo;Trusted_Connection=true" providerName="System.Data.sqlClient"/></connectionStrings>

ps：连接字符串中的Trusted_Connection：Trusted_Connection=false/no时，在连接中要必须指定密码和用户名,当没指明Trusted_Connection的值时,默认是false/no。当Trusted_Connection=true/yes时。说明server database已设置为用信任连接了，连接中可以不用指明用户名和密码(当然：你指定用户名和密码也不会去验证。是多此一举)。此时将使用当前的 Windows 帐户凭据进行身份验证。

 <add name="sutDb" connectionString="Data Source=.;database=Demo;uid=sa;pwd=123;AttachDBFilename=|DataDirectory|\Demo.mdf;" providerName="System.Data.SqlClient"/>

class StuDbContext : DbContext
{

    //配置文件中为stuDb的连接字符串，如果没找到，就会以stuDb做为数据库名，创建数据库。   但如果写成name=stuDb格式。当没找到会报异常，No connection string named 'stuDb' could be found in the application config file.

public StuDbContext() : base("stuDb")    { } 

  public DbSet<Students> student { get; set; }

 }

 static void Select(){StudentContext db = new StudentContext();var student = from su in db.studentselect su;foreach (var item in student){string result = string.Format("{0}\t{1}\t{2}\t{3}", item.stuId, item.stuAge, item.stuAdress, item.stuName);Console.WriteLine(result);}//同样可以查询var st = from su in db.studentselect new{name = su.stuName,age = su.stuAge,id = su.stuId,adress = su.stuAdress};st.ToList().ForEach(item => Console.WriteLine(item));Console.ReadKey();}

        /// <summary>/// 修改数据/// </summary>static void Update(){//修改数据是根据主键来找数据的。这也说明建表必须要有keyStudent st = new Student();st.stuId = 1;  //根据id找到记录st.stuName = "释小龙";st.stuAdress = "香港";st.stuAge = 20;StudentContext db = new StudentContext();//修改方式一：把DbContext转换成ObjectContext进行数据库更新ObjectContext context = ((IObjectContextAdapter)db).ObjectContext;  //IObjectContextAdapter所需命名空间：using System.Data.Entity.Infrastructure
            db.student.Attach(st);context.ObjectStateManager.ChangeObjectState(st, EntityState.Modified);  //db.SaveChanges();//修改方式二：直接用DbContext更新db.student.Attach(st);  //待更新的数据附加到db。也就是上下文db.Entry(st).State = EntityState.Modified; //EntityState 得引用 System.Data.Entity    告诉上下文。状态是修改。 同理把EntityState.Deleted就是删除。//db.Entry<Student>(st).State = EntityState.Modified;db.SaveChanges();  //保存}

<?xml version="1.0" encoding="utf-8"?>
<!--有关如何配置 ASP.NET 应用程序的详细信息，请访问http://go.microsoft.com/fwlink/?LinkId=301880-->
<configuration><configSections><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /></configSections><appSettings><add key="webpages:Version" value="3.0.0.0" /><add key="webpages:Enabled" value="false" /><add key="ClientValidationEnabled" value="true" /><add key="UnobtrusiveJavaScriptEnabled" value="true" /></appSettings><connectionStrings><add name="EFDbContext" connectionString="Data Source=.;Initial Catalog=数据库;User ID=SA;Password=123456" providerName="System.Data.SqlClient" /></connectionStrings><system.web><compilation debug="true" targetFramework="4.5.1" /><httpRuntime targetFramework="4.5.1" /></system.web><entityFramework><defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" /><providers><provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" /></providers></entityFramework>
</configuration>

View Code