003-SqlHelper.cs/Web.config

 <?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=169433
   -->

 <configuration>
     <system.web>
       <compilation debug="true" targetFramework="4.5" />
       <httpRuntime targetFramework="4.5" />
     </system.web>
   <connectionStrings>
     <add name="connStr" connectionString="server=.;database=web1;uid=sa;pwd=123"/>
   </connectionStrings>
 </configuration>

 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Data.SqlClient;
 using System.Linq;
 using System.Web;

 namespace t3_TypeInfo
 {
     public static class SqlHelper
     {
         private static string connStr =
             System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;

         public static DataTable GetList()
         {
             using (SqlConnection conn=new SqlConnection(connStr))
             {
                 string sql = "select * from typeinfo order by typeid desc";
                 SqlDataAdapter sda=new SqlDataAdapter(sql,conn);
                 DataTable dt=new DataTable();
                 sda.Fill(dt);
                 return dt;
             }
         }

         public static TypeInfo GetById(int id)
         {
             using (SqlConnection conn=new SqlConnection(connStr))
             {
                 string sql = "select * from typeinfo where typeid=@id";
                 SqlParameter p=new SqlParameter("@id",id);

                 SqlCommand cmd=new SqlCommand(sql,conn);
                 cmd.Parameters.Add(p);

                 conn.Open();
                 TypeInfo ti=new TypeInfo();
                 SqlDataReader sdr = cmd.ExecuteReader();
                 sdr.Read();
                 ti.TypeId = Convert.ToInt32(sdr["TypeId"]);
                 ti.TypeTitle = sdr["TypeTitle"].ToString();

                 return ti;
             }
         }

         public static int Add(string title)
         {
             using (SqlConnection conn = new SqlConnection(connStr))
             {
                 string sql = "insert into typeinfo values(@title)";
                 SqlParameter p=new SqlParameter("@title",title);

                 SqlCommand cmd=new SqlCommand(sql,conn);
                 cmd.Parameters.Add(p);

                 conn.Open();
                 return cmd.ExecuteNonQuery();
             }
         }

         public static int Edit(TypeInfo ti)
         {
             using (SqlConnection conn=new SqlConnection(connStr))
             {
                 string sql = "update typeinfo set typeTitle=@title where typeid=@id";
                 SqlParameter[] ps =
                 {
                     new SqlParameter("@id", ti.TypeId),
                     new SqlParameter("@title", ti.TypeTitle)
                 };

                 SqlCommand cmd=new SqlCommand(sql,conn);
                 cmd.Parameters.AddRange(ps);

                 conn.Open();
                 return cmd.ExecuteNonQuery();
             }
         }

         public static int Remove(int id)
         {
             using (SqlConnection conn=new SqlConnection(connStr))
             {
                 string sql = "delete from typeinfo where typeid=@id";
                 SqlParameter p=new SqlParameter("@id",id);

                 SqlCommand cmd=new SqlCommand(sql,conn);
                 cmd.Parameters.Add(p);

                 conn.Open();
                 return cmd.ExecuteNonQuery();
             }
         }
     }
 }