初识三层架构(4)

  DAL
 1 using System;
 2 using 三层架构.Model;
 3 using System.Data.SqlClient;
 4 using System.Data;
 5 using System.Collections.Generic;
 6
 7 namespace 三层架构.DAL
 8 {
 9     class PersonDAL
10     {
11         //增加字段
12         public static int AddNew(Person model)//返回新添加字段的主键
13         {
14          object obj= SQLHelper.ExecuteScalar("insert into T_person(Age,Name) output inserted.id values(@Age,@Name)",new SqlParameter("Age",model.Age),new SqlParameter("Name",model.Name));
15          return Convert.ToInt32(obj);
16         }
17         //删除操作www.2cto.com
18         public static int Delete(int id)
19         {
20             return SQLHelper.ExecuteNonQuery("delete from T_person where id=@id", new SqlParameter("id", id));
21         }
22         //更新数据
23         public static int UpDate(Person model)
24         {
25             return SQLHelper.ExecuteNonQuery("update T_Person set age=@age,name=@name where id=@id",new SqlParameter("age",model.Age), new SqlParameter("name",model.Name),new SqlParameter("id",model.Id));
26         }  
27         //查询数据
28         public static Person GetPerson(int id)
29         {
30          DataTable dt=SQLHelper.ExecuteDataTable("select * from T_Person where id=@id",new SqlParameter("id",id));
31          if (dt.Rows.Count <= 0)
32          {
33              return null;
34          }
35          else if (dt.Rows.Count ==1)
36          {