ActiveRecord学习笔记（五）：处理继承关系

　　本文主要介绍了如何使用Castle.ActiveRecord来处理继承关系。
　　本文涉及两个实体类：基类(User)、子类(Employee)。以下是类图：


本文主要内容：
１．编写数据库脚本
２．JoinedBase和JoinedKey属性说明
３．编写实体类
４．编写调用代码

一、编写数据库脚本
　　其实本文涉及的数据表在前面的笔记中都出现过！

Create Table Users
(
  ID int identity(1,1) primary key,
  LoginName Varchar(50) not null,
  Password Varchar(20) not null
)

Create Table Employees
(
  ID int primary key,
  Salary money
)

二、JoinedBase和JoinedKey属性说明
　　JoinedBase属性：该属性是ActiveRecord属性子属性，用于基类中；
　　JoinedKey性性：该属性用在子类中，用于代替PrimaryKey的位置；

三、编写实体类
　　基类：User.cs

/**////jailusd@hotmail.com
///2006-09-24

using System;
using System.Collections.Generic;
using System.Text;

using Castle.ActiveRecord;

namespace Inherit
{
    [ActiveRecord("Users"),JoinedBase]  //JoinedBase
    public class User : ActiveRecordBase
    {
        private int intID;
        private string strUserName;
        private string strUserPsd;

        public User()
        {
            intID = 0;
            strUserName = string.Empty;
            strUserPsd = string.Empty;
        }
    
        [PrimaryKey(PrimaryKeyType.Identity,"ID")]
        public int ID
        {
            get
            {
                return intID;
            }
            set
            {
                intID = value;
            }
        }

        /**//// <summary>
        /// 用户名
        /// </summary>
        [Property("LoginName")]
        public string Name
        {
            get
            {
                return strUserName;
            }
            set
            {
                strUserName = value;
            }
        }

        /**//// <summary>
        /// 用户密码
        /// </summary>
        [Property("Password")]
        public string Password
        {
            get
            {
                return strUserPsd;
            }
            set
            {
                strUserPsd = value;
            }
        }
    }
}

　　子类：Employee.cs

/**////jailusd@hotmail.com
///2006-09-24

using System;
using System.Collections.Generic;
using System.Text;

using Castle.ActiveRecord;

namespace Inherit
{
    [ActiveRecord("Employees")]
    public class Employee : User
    {
        private int intEID;
        private decimal decimalSalary;

        public Employee()
        {
            intEID = 0;
            decimalSalary = 0;
        }

        [JoinedKey("ID")]   //JoinedKey代替PrimaryKey的位置
        public int EID
        {
            get
            {
                return intEID;
            }
            set
            {
                intEID = value;
            }
        }
        
        /**//// <summary>
        /// 薪水
        /// </summary>
        [Property]
        public decimal Salary
        {
            get
            {
                return decimalSalary;
            }
            set
            {
                decimalSalary = value;
            }
        }
    }
}

四、编写调用代码（只列出添加Employee的代码）

private void button2_Click(object sender, EventArgs e)
{
    IConfigurationSource source = System.Configuration.ConfigurationManager.GetSection("activerecord") as IConfigurationSource;
    ActiveRecordStarter.Initialize(source, typeof(Inherit.Employee), typeof(Inherit.User));

    //使用事务处理
    using (TransactionScope tran = new TransactionScope())
    {
        Inherit.Employee objEmployee = new Inherit.Employee();

        objEmployee.Name = "jailu";
        objEmployee.Password = "123456789";
        objEmployee.Salary = 1000;

        objEmployee.Save();
    }
}