Simple Layer-3 Review, layer-3 Review

Simple Layer-3 Review, layer-3 Review

I haven't reviewed it for a long time. I learned it before. If I don't review it, I will forget it. So I should review more and learn more! Not to mention nonsense. Start ~~~~

First, the database script:

USE [DB_MyStudentLife]GO/****** Object:  Table [dbo].[MyClass]    Script Date: 11/26/2015 22:19:31 ******/SET ANSI_NULLS ONGOSET QUOTED_IDENTIFIER ONGOCREATE TABLE [dbo].[MyClass](    [C_ID] [INT] NOT NULL,    [C_Name] [NVARCHAR](200) NOT NULL,    [C_Descr] [NVARCHAR](MAX) NOT NULL,PRIMARY KEY CLUSTERED (    [C_ID] ASC)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]) ON [PRIMARY]GO

Then there is the entity Layer Code:

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; namespace Entity {public class ClassEntity {// <summary> // class ID /// </summary> public int CID {get; set ;} /// <summary> /// class name /// </summary> public string CName {get; set ;} /// <summary> /// class description /// </summary> public string CDescription {get; set ;}}}

Then the DAL layer:

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; using System. configuration; using System. data; using System. data. sqlClient; namespace DAL {public class SQLHelper {// <summary> // obtain the connection string /// </summary> public static string ConnectionString {get {return ConfigurationManager. connectionStrings ["ConnectionString"]. connectionString ;}}// /<Summary> // obtain the Datatable data // </summary> // <param name = "SQL"> SQL statement </param> // <param name = "type"> command type </param> /// <param name = "param"> parameter list </param> /// <returns> returns the DataTable type </returns> public static DataTable GetDataTable (string SQL, commandType type, params SqlParameter [] param) {// create the connection object using (SqlConnection conn = new SqlConnection (ConnectionString) {// create the data adapter object using (SqlDataAdapter sda = New SqlDataAdapter (SQL, conn) {if (param! = Null) {sda. selectCommand. parameters. addRange (param);} sda. selectCommand. commandType = type; DataTable table = new DataTable (); sda. fill (table); return table ;}}}}}

Using Entity; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; using System. data; using System. data. sqlClient; namespace DAL {public class ClassDAL {/// <summary> /// obtain the class List data /// </summary> /// <returns> </returns> public List <classEntity> GetList () {string SQL = "SELECT * FROM dbo. myClass; "; DataTable table = SQLHelper. getDataTable (SQL, CommandType. text); // you cannot directly create an object List <ClassEntity> classListModel = null; // The table is not empty if (table. rows. count> 0) {// here new is to be created. The object classListModel = new List <ClassEntity> (); ClassEntity model = null; foreach (DataRow row in table. rows) {model = new ClassEntity (); // load the data LoadEntity (row, model); classListModel. add (model) ;}}return classListModel ;}/// <summary> /// load data /// </summary> /// <param Name = "row"> </param> // <param name = "model"> </param> public void LoadEntity (DataRow row, ClassEntity model) {if (row ["C_ID"]! = Null) {model. CID = Convert. ToInt32 (row ["C_ID"]);} if (row ["C_Name"]! = Null) {model. CName = row ["C_Name"]. ToString ();} if (row ["C_Descr"]! = Null) {model. CDescription = row ["C_Descr"]. ToString ();}}}}

Then there is the BLL layer:

Using DAL; using Entity; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; namespace BLL {public class ClassBLL {ClassDAL dal = new ClassDAL (); /// <summary> /// obtain the Class List /// </summary> /// <returns> </returns> public List <ClassEntity> GetList () {return dal. getList ();}}}

Then there is a Web project:

using BLL;using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;namespace Web{    public partial class Default : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            ClassBLL bll = new ClassBLL();           GridView1.DataSource= bll.GetList();           GridView1.DataBind();        }    }}

:

The code at the DAL layer and the red part of the table. Note that if an error occurs in the instantiation position, the following result is displayed: