在C#中实现3层架构(3)
///
/// Function Add new customer. Calls
/// the function in Data layer.
///
public void Add()
{
cusData.Add(this);
}
///
/// Function Update customer details.
/// Calls the function in Data layer.
///
public void Update()
{
cusData.Update(this);
}
///
/// Function Find customer. Calls the
/// function in Data layer.
/// It returns the details of the customer using
/// customer ID via a Dataset to GUI tier.
///
public DataSet Find(String str)
{
if (str == "")
throw new Exception("Please provide ID to search");
DataSet data = null;
data = cusData.Find(str);
return data;
}
}
}
数据访问层
数据层包括处理MS Access数据库的细节。所有这些细节都是透明的，不会影响到商业逻辑层。数据访问层有个指向商业逻辑层的引用BOCustomer cus。为了应用方便并且支持其他数据库。
using System;
using System.Data.OleDb;
using System.Data;
namespace _3tierarchitecture
{
///
/// Summary description for DACustomer.
///
public class DACustomer
{
private OleDbConnection cnn;
//change connection string as per the
//folder you unzip the files
private const string CnnStr =
"Provider=Microsoft.Jet.OLEDB.4.0;Data " +
"Source= D:""Rahman_Backup""Programming""" +
"Csharp""3tierarchitecture""customer.mdb;";
//local variables
private String strTable="";
private String strFields="";
private String strValues="";
private String insertStr="";
//this needs to be changed based on customer
//table fields' Name of the database!
private const String thisTable = "tblCustomer";
private const String cus_ID = "CUS_ID";
private const String cus_LName = "CUS_L_NAME";
private const String cus_FName = "CUS_F_NAME";
private const String cus_Tel = "CUS_TEL";
private const String cus_Address = "CUS_ADDRESS";
public DACustomer()
{
}