三层架构实现增删的简单实例

首先建一个web.config的窗体，添加
<appSettings>
    <add key="conn" value="server=.;database=test;integrated security=true"/>
  </appSettings>
  <connectionStrings/>字段

简单页面设计：

     　　　　　　　　　　　　　　　　　　

在DAL层创建连接：
SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["conn"].ToString());


public DataSet GetAll()
{
   SqlDataAdapter da=new SqlDataAdapter（“select * from student_info ”,conn）;
   DataSet ds=new DataSet();
   da.Fill(ds);
   return ds;
}

增加：
public void Insert(int id,int age,string name,string sex)
{
   SqlCommand cmd=new SqlCommand("insert into student_info values("+id+","+age+",'"+name+"','"+sex+"')",conn);
   conn.open();
   cmd.ExecuteNonQuery();
   conn.Close();
}
删除
public void Delete(int sid)
{
 SqlCommand cmd=new SqlCommand("delete from student_infor where id="+sid+"",conn);
 conn.open();
 cmd.ExecuteNonQuery();
 conn.Close();

}

public class BLL_Class
    {
        private int id, age,sid;
        private string name, sex;
        public int ID
        {
            get { return id; }
            set { id = value; }
        }
        public int Age
        {
            get { return age; }
            set { age = value; }
        }
        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        public string Sex
        {
            get { return sex; }
            set { sex = value; }
        }

        public int Sid
        {
            get { return sid; }
            set { sid = value; }
        }
        DAL.DAl_Class DC = new DAL.DAl_Class();

        public DataSet Bind()
        {
            return DC.GetALL();
        }
        public void Insert_info()
        {
            DC.Insert(ID, Age, Name, Sex);
        }
        public void Delete_info()
        {
            DC.Delete(Sid);
        }
    }

Bll.Bll_class BC;
 protected void Page_Load(object sender, EventArgs e)
{
     BC = new BLL.BLL_Class();
     this.GridView1.DataSource = BC.Bind();
     this.GridView1.DataBind();
}
//添加
protected void Button1_Click(object sender, EventArgs e)
{
   BC.ID = Convert.ToInt32(TextBox1.Text.Trim().ToString());
   BC.Age = Convert.ToInt32(TextBox2.Text);
   BC.Name = this.TextBox4.Text;
   BC.Sex = this.TextBox3.Text;
   BC.Insert_info();
}
删除
protected void Button2_Click(object sender, EventArgs e)
{
   BC.Sid = Convert.ToInt32(TextBox1.Text.Trim().ToString());
   BC.Delete_info();
}