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：

数据层

 1 在DAL层创建连接：
 2 SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["conn"].ToString());
 3 
 4 
 5 public DataSet GetAll()
 6 {
 7    SqlDataAdapter da=new SqlDataAdapter（“select * from student_info ”,conn）;
 8    DataSet ds=new DataSet();
 9    da.Fill(ds);
10    return ds;
11 }
12 
13 增加：
14 public void Insert(int id,int age,string name,string sex)
15 {
16    SqlCommand cmd=new SqlCommand("insert into student_info values("+id+","+age+",'"+name+"','"+sex+"')",conn);
17    conn.open();
18    cmd.ExecuteNonQuery();
19    conn.Close();
20 }
21 删除
22 public void Delete(int sid)
23 {
24  SqlCommand cmd=new SqlCommand("delete from student_infor where id="+sid+"",conn);
25  conn.open();
26  cmd.ExecuteNonQuery();
27  conn.Close();
28 
29 }

逻辑层

 1 public class BLL_Class
 2     {
 3         private int id, age,sid;
 4         private string name, sex;
 5         public int ID
 6         {
 7             get { return id; }
 8             set { id = value; }
 9         }
10         public int Age
11         {
12             get { return age; }
13             set { age = value; }
14         }
15         public string Name
16         {
17             get { return name; }
18             set { name = value; }
19         }
20         public string Sex
21         {
22             get { return sex; }
23             set { sex = value; }
24         }
25 
26         public int Sid
27         {
28             get { return sid; }
29             set { sid = value; }
30         }
31         DAL.DAl_Class DC = new DAL.DAl_Class();
32 
33         public DataSet Bind()
34         {
35             return DC.GetALL();
36         }
37         public void Insert_info()
38         {
39             DC.Insert(ID, Age, Name, Sex);
40         }
41         public void Delete_info()
42         {
43             DC.Delete(Sid);
44         }
45     }

显示层

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();
}