【asp.net】MVC中通过三层架构获取数据库值的示例（包括CSHTML前台和后台Model/BLL/DAL）

一、获取数据库中某一条记录字段的值

1、数据库中的新建一个表CSJ

2、分别创建五个文件

(1)、Controllers中添加【CsjController.cs】和View中【Index.cshtml】

CsjController.cs页面代码

using System;
using System.Collections.Generic;
using CityCard.Web.Admin.Model;
using System.Linq;
using System.Text;
using System.Web.Mvc;
using System.Web;
using System.Drawing;
using System.Net;  //LoginType 需要

namespace CityCard.Web.Admin.Controllers
{
    public class CsjController : Controller
    {
        public ActionResult Index()
        {
             var Bll_User = new CityCard.Web.Admin.BLL.Csj();   
             ViewData["User"] = Bll_User.Get_FieldValue("关羽") ; // 获取姓名等于关羽的记录
            return View();
        }

    }
}

Index.cshtml页面代码

@{
    var user1 = ViewData["User"] as CityCard.Web.Admin.Model.Csj;
    Layout = null; // 不显示默认加载的页面
}

<h2>--- 从数据表中读取一条记录中各字段的值 --- </h2>

<h2> 编号：@Html.Raw(user1.ID) </h2>
<h2> 姓名：@Html.Raw(user1.Name) </h2>
<h2> 年龄：@Html.Raw(user1.Old) </h2>

（2）、BLL增加csj.cs（业务逻辑层，程序实现逻辑）

csj.cs页面代码

using System;
using System.Data;
using System.Collections.Generic; 
using CityCard.Web.Admin.Model;
using System.Collections.Specialized;
namespace CityCard.Web.Admin.BLL
{
    /// <summary>
    /// Sys_Employee
    /// </summary>
    public partial class Csj
    {
        private readonly CityCard.Web.Admin.DAL.Csj dal = new CityCard.Web.Admin.DAL.Csj();
        public Csj()
        { }
        #region BasicMethod

        public CityCard.Web.Admin.Model.Csj Get_FieldValue(string Code)
        {
            return dal.Get_FieldValue(Code); // 
        }

        #endregion BasicMethod
    }
}

（3）、Model增加Csj.cs（数据表类，映射数据库表结构）

csj.cs页面代码

using System;
using Dapper.Contrib.Extensions;
namespace CityCard.Web.Admin.Model
{
    [Serializable]
    [Table("[Csj]")]
    public partial class Csj
    {
        public Csj()
        {
        }
        #region Model
        private int _id;
        private string _name;
        private int _old;
        public int ID
        {
            set { _id = value; }
            get { return _id; }
        }
        public string Name
        {
            set { _name = value; }
            get { return _name; }
        }
        public int Old
        {
            set { _old = value; }
            get { return _old; }
        }
        #endregion Model
    }
}

（4）、DAL增加Csj.cs（数据库操作命令层）

using System;
using System.Data;
using System.Text;
using System.Data.SqlClient;
using System.Collections.Specialized;
using CodeMagic.DBUtility;
using System.Linq;
using System.Collections.Generic;

using CityCard.Common.Extensions;//ToMD5需要

namespace CityCard.Web.Admin.DAL
{
    /// <summary>
    /// 数据访问类:User
    /// </summary>
    public partial class Csj
    {
        public Csj()
        { }
        #region BasicMethod
        public CityCard.Web.Admin.Model.Csj Get_FieldValue(string Code)
        {
            var query = "select * from Csj where Name=@Code";
            return DbHelperSQL.Query<CityCard.Web.Admin.Model.Csj>(query, new { Code = Code }).FirstOrDefault();
        }

        #endregion
    }
}

二、获取数据库中所有记录字段的值

1、数据库中的新建一个表CSJ

2、分别创建五个文件

(1)、Controllers中添加【CsjController.cs】和View中【Index.cshtml】

CsjController.cs页面代码

using System;
using System.Collections.Generic;
using CityCard.Web.Admin.Model;
using System.Linq;
using System.Text;
using System.Web.Mvc;
using System.Web;
using System.Drawing;
using System.Net;  //LoginType 需要

namespace CityCard.Web.Admin.Controllers
{
    public class CsjController : Controller
    {
        public ActionResult Index()
        {
             var Bll_User = new CityCard.Web.Admin.BLL.Csj();   
              ViewData["UserAll"] = Bll_User.GeTabletAll("1", "关羽");  // 获取表的所有记录
            return View();
        }

    }
}

Index.cshtml页面代码

@{
    //var user1 = ViewData["User"] as CityCard.Web.Admin.Model.Csj;
    Layout = null; // 不显示默认加载的页面
    var UserAll = ViewData["UserAll"] as List<CityCard.Web.Admin.Model.Csj>;
}
<h2>编号|姓名|年龄</h2>
@foreach (var item in UserAll)
{
    <h2>@item.ID|@item.Name|@item.Old</h2>
}

（2）、BLL增加csj.cs（业务层）

csj.cs页面代码

using System;
using System.Data;
using System.Collections.Generic; 
using CityCard.Web.Admin.Model;
using System.Collections.Specialized;
namespace CityCard.Web.Admin.BLL
{
    /// <summary>
    /// Sys_Employee
    /// </summary>
    public partial class Csj
    {
        private readonly CityCard.Web.Admin.DAL.Csj dal = new CityCard.Web.Admin.DAL.Csj();
        public Csj()
        { }
        #region BasicMethod

        public List<CityCard.Web.Admin.Model.Csj> GeTabletAll(string Code, string m_name)
        {
            return dal.GeTabletAll(Code,m_name);
        }
        #endregion BasicMethod
    }
}

（3）、Model增加Csj.cs（数据表结构）

csj.cs页面代码

using System;
using Dapper.Contrib.Extensions;
namespace CityCard.Web.Admin.Model
{
    [Serializable]
    [Table("[Csj]")]
    public partial class Csj
    {
        public Csj()
        {
        }
        #region Model
        private int _id;
        private string _name;
        private int _old;
        public int ID
        {
            set { _id = value; }
            get { return _id; }
        }
        public string Name
        {
            set { _name = value; }
            get { return _name; }
        }
        public int Old
        {
            set { _old = value; }
            get { return _old; }
        }
        #endregion Model
    }
}

（4）、DAL增加Csj.cs（数据库操作命令层）

using System;
using System.Data;
using System.Text;
using System.Data.SqlClient;
using System.Collections.Specialized;
using CodeMagic.DBUtility;
using System.Linq;
using System.Collections.Generic;

using CityCard.Common.Extensions;//ToMD5需要

namespace CityCard.Web.Admin.DAL
{
    /// <summary>
    /// 数据访问类:User
    /// </summary>
    public partial class Csj
    {
        public Csj()
        { }
        #region BasicMethod
        public List<CityCard.Web.Admin.Model.Csj> GeTabletAll(string Code,string m_name)
        {
            var query = "select * from Csj where Id>@Code and Name=@m_name";
            return DbHelperSQL.Query<CityCard.Web.Admin.Model.Csj>(query, new { Code = Code, m_name= m_name }).ToList();
        }

        #endregion
    }
}