[学习笔记]工厂方法用于数据库开发

摘自《大话设计模式》一书。

程序入口：

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 using System.Reflection;
 5 using System.Configuration;
 6 
 7 namespace 抽象工厂模式
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             User user = new User();
14             Department dept = new Department();
15 
16             IUser iu = DataAccess.CreateUser();
17 
18             iu.Insert(user);
19             iu.GetUser(1);
20 
21             IDepartment id = DataAccess.CreateDepartment();
22             id.Insert(dept);
23             id.GetDepartment(1);
24 
25             Console.Read();
26         }
27     }
28 }

Main

工厂方法：

 1 class DataAccess
 2     {
 3         private static readonly string AssemblyName = "抽象工厂模式";
 4         private static readonly string db = ConfigurationManager.AppSettings["DB"];
 5         
 6         public static IUser CreateUser()
 7         {
 8             string className = AssemblyName + "." + db + "User";
 9             return (IUser)Assembly.Load(AssemblyName).CreateInstance(className);
10         }
11 
12         public static IDepartment CreateDepartment()
13         {
14             string className = AssemblyName + "." + db + "Department";
15             return (IDepartment)Assembly.Load(AssemblyName).CreateInstance(className);
16         }
17     }

数据实体类User和Department：

 1    class User
 2     {
 3         private int _id;
 4         public int ID
 5         {
 6             get { return _id; }
 7             set { _id = value; }
 8         }
 9 
10         private string _name;
11         public string Name
12         {
13             get { return _name; }
14             set { _name = value; }
15         }
16     }

 1  class Department
 2     {
 3         private int _id;
 4         public int ID
 5         {
 6             get { return _id; }
 7             set { _id = value; }
 8         }
 9 
10         private string _deptName;
11         public string DeptName
12         {
13             get { return _deptName; }
14             set { _deptName = value; }
15         }
16     }

数据操作：

1   interface IUser
2     {
3         void Insert(User user);
4 
5         User GetUser(int id);
6     }

 1   class SqlserverUser : IUser
 2     {
 3         public void Insert(User user)
 4         {
 5             Console.WriteLine("在Sqlserver中给User表增加一条记录");
 6         }
 7 
 8         public User GetUser(int id)
 9         {
10             Console.WriteLine("在Sqlserver中根据ID得到User表一条记录");
11             return null;
12         }
13     }

SqlserverUser : IUser

 1  class AccessUser : IUser
 2     {
 3         public void Insert(User user)
 4         {
 5             Console.WriteLine("在Access中给User表增加一条记录");
 6         }
 7 
 8         public User GetUser(int id)
 9         {
10             Console.WriteLine("在Access中根据ID得到User表一条记录");
11             return null;
12         }
13     }

AccessUser : IUser

1  interface IDepartment
2     {
3         void Insert(Department department);
4 
5         Department GetDepartment(int id);
6     }

 1  class SqlserverDepartment : IDepartment
 2     {
 3         public void Insert(Department department)
 4         {
 5             Console.WriteLine("在Sqlserver中给Department表增加一条记录");
 6         }
 7 
 8         public Department GetDepartment(int id)
 9         {
10             Console.WriteLine("在Sqlserver中根据ID得到Department表一条记录");
11             return null;
12         }
13     }

SqlserverDepartment : IDepartment

 1  class AccessDepartment : IDepartment
 2     {
 3         public void Insert(Department department)
 4         {
 5             Console.WriteLine("在Access中给Department表增加一条记录");
 6         }
 7 
 8         public Department GetDepartment(int id)
 9         {
10             Console.WriteLine("在Access中根据ID得到Department表一条记录");
11             return null;
12         }
13     }

AccessDepartment : IDepartment

以前总是把IUser接口这样的操作也写到数据库视图中，老是感觉不和谐。从抽象的角度看，数据库操作并不是实体User的必须方法，而且我也不是什么时候都需要调用数据的，如果把实体中增加了数据库操作方法，调用者恶意调用多麻烦！这里再分一个抽象的IUser专门管理数据库操作还是很好的。

[学习笔记]工厂方法用于数据库开发

相关推荐