考:清華大學出版社三層結構

1.創建數據層

   創建對客戶進行操作的存儲過程.存儲過程是數據層的一部分,可以在業務層中訪問它,以實現表示層的某個地方要執行的功能.這裏不再說明把數據訪問邏輯放在單獨一層的優點.

   在Store數據庫中創建存儲過程GetCustomerByEmail,該存儲過程把登錄頁面中輸入的EMAIL作爲參數,查找EMAIL地址爲該參數值的客戶,然後以輸出參數的形式返回該客戶的ID,名字,密碼 ,地址,國家,電話和傳真.代碼如下:

create procedure GetCustomerByEmail

(

      @Email nvarchar(50) = null,

      @CustomerID int OUTPUT,

      @Name nvarchar(50) OUTPUT,

      @password nvarchar(50) OUTPUT,

      @Address nvarchar(250) OUTPUT,

      @Country nvarchar(250) OUTPUT,

      @PhoneNumber nvarchar(250) OUTPUT,

      @Fax nvarchar(250) OUTPUT

   )

AS

      SET NOCOUNT ON

SELECT

      @CustomerID = c.CutomerID,

      @Name = c.FullName,

      @Password = c.Password,

      @Address = a.Address,

      @Country = a.Country,

      @PhoneNumber = a.PhoneNumber,

      @Fax = a.Fax

FROM Customers c,Addresses a

      WHERE c.EmailAddree = @Email

      AND a.CustomerId = c.CustomerId

   IF @@Rowcount < 1

SELECT

      @CustomerID = 0

GO

(

      @Email nvarchar(50) = null,

      @CustomerID int OUTPUT,

      @Name nvarchar(50) OUTPUT,

      @password nvarchar(50) OUTPUT,

      @Address nvarchar(250) OUTPUT,

      @Country nvarchar(250) OUTPUT,

      @PhoneNumber nvarchar(250) OUTPUT,

      @Fax nvarchar(250) OUTPUT

   )

AS

      SET NOCOUNT ON

SELECT

      @CustomerID = c.CutomerID,

      @Name = c.FullName,

      @Password = c.Password,

      @Address = a.Address,

      @Country = a.Country,

      @PhoneNumber = a.PhoneNumber,

      @Fax = a.Fax

FROM Customers c,Addresses a

      WHERE c.EmailAddree = @Email

      AND a.CustomerId = c.CustomerId

   IF @@Rowcount < 1

SELECT

      @CustomerID = 0

GO

2.創建業務層

業務層是存取數據的類,該類與數據層和表示層(用戶界面)交戶作用,在需要時從表示層獲得數據,並將數據存入數據庫,也可以從數據層獲得數據,並將數據發送給表示層(用戶界面).

(1)在"解決方案資源管理器"中,選擇解決方案下的GoShop項目,右擊,再將鼠標指向"添加",然後選擇"添加類"命令.

   (2)在"類別"窗口中選擇"本地項目",然後在"模板"窗口中選擇"代碼文件".在"名稱"文本框中,輸入CustomerDB.

   (3)單擊"打開",代碼如下:

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Data.SqlClient;



namespace Goshop{



/// <summary>

/// Class1 的摘要說明

/// </summary>

public class Customer

{



   public string Name;

        public string Email;

        public string Password;

        public string Country;

        public string Addresss;

        public string PhoneNumber;

        public string Fax;

        public int CustomerID;



}

    public class CustomerDB

    {

          private string ConnectionString

          {

              get

              {

                  string strConn;

                  strConn = "Data Source =(local);";

                  strConn +="Initial Catalog = Store;";

                 return strConn ;

              }

          }

        public Customer GetCustomerByEmail(string Email)

    {

        SqlConnection myconnection = new SqlConnection(ConnectionString);

        SqlCommand mycommand = new SqlCommand("GetCustomerByEmail",myconnection);

        mycommand.CommandType = CommandType.StoredProcedure;

        SqlParameter parameterCustomerID = new SqlParameter("@CustomerID",SqlDbType.Int,4);

        parameterCustomerID.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterCustomerID);

        SqlParameter parameterFullName = new SqlParameter("@Name",SqlDbType.NVarChar,50);

        parameterFullName.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterFullName);

        SqlParameter parameterEmail = new SqlParameter("@Email",SqlDbType.NVarChar,50);

        parameterEmail.Value = Email;

        mycommand.Parameters.Add(parameterEmail);

        SqlParameter parameterPassword = new SqlParameter("@Password",SqlDbType.NVarChar,50);

        parameterPassword.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterPassword);

        SqlParameter parameterAddress = new SqlParameter("@Address",SqlDbType.NVarChar,255);

        parameterAddress.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterAddress);

        SqlParameter parameterCountry = new SqlParameter("@Country",SqlDbType.NVarChar,40);

        parameterCountry.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterCountry);

        SqlParameter parameterPhoneNumber = new SqlParameter("@PhoneNuber",SqlDbType.NVarChar,30);

        parameterPhoneNumber.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterPhoneNumber);

        SqlParameter parameterFax = new SqlParameter("@Fax",SqlDbType.NVarChar,30);

        parameterFax.Direction = ParameterDirection.Output;

        mycommand.Parameters.Add(parameterFax);

        myconnection.Open();

        mycommand.ExecuteNonQuery();

        myconnection.Close();

        int customerId =(int)(parameterCustomerID.Value);

        if(customerId == 0)

        {

            return null;

        }

        else

        {

            Customer myCustomer = new Customer();

            myCustomer.Name = (string)parameterFullName.Value;

            myCustomer.Password = (string)parameterPassword.Value;

            myCustomer.Email = (string)parameterEmail.Value;

            myCustomer.Addresss = (string)parameterAddress.Value;

            myCustomer.Country = (string)parameterCountry.Value;

            myCustomer.PhoneNumber = (string)parameterPhoneNumber.Value;

            myCustomer.Fax = (string)parameterFax.Value;

            myCustomer.CustomerID = customerId;

            return myCustomer;

        }



    }

    }

}