Castle ActiveRecord学习实践（4）：实现One-Many关系的映射 　

建表
CREATE TABLE [dbo].[Employees] (
[Employeesid] [int] IDENTITY (1, 1) NOT NULL ,
[LogonName] [varchar] (40) COLLATE Chinese_PRC_CI_AS NULL ,
[LastLogon] [datetime] NULL
) ON [PRIMARY]
GO

CREATE TABLE Posts (
post_id int IDENTITY(1, 1) PRIMARY KEY,
post_Employeesid int,
post_title varchar(50),
post_contents text,
post_created datetime,
)

实体类
Employees类
using System;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
using System.Collections;
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 Castle.ActiveRecord;
using Castle.ActiveRecord.Framework;
using Castle.ActiveRecord.Framework.Config;
using Castle.ActiveRecord.Framework.Internal;
using Castle.ActiveRecord.Framework.Scopes;
using Castle.ActiveRecord.Framework.Validators;
using Castle.ActiveRecord.Queries.Modifiers;
using Castle.ActiveRecord.Queries;

/// <summary>
/// Employees 的摘要说明
/// </summary>

[ActiveRecord(Table="Employees")]
public class Employees : ActiveRecordBase
{
private int _Employeesid;
private string _LogonName;
private DateTime _LastLogon;
private IList _posts;

[PrimaryKey(PrimaryKeyType.Identity, Column = "Employeesid")]
public int Employeesid
{
get { return _Employeesid; }
set { _Employeesid = value; }
}
[Property(Column = "LogonName")]
public string LogonName
{
get { return _LogonName; }
set { _LogonName = value; }
}
[Property(Column = "LastLogon")]
public DateTime LastLogon
{
get { return _LastLogon; }
set { _LastLogon = value; }
}
//typeof:子表实例
//Table:子表名
//ColumnKey:子表字段
//Cascade:从主表到子表的级联关系：一般在主表上设为ALL
//Inverse：控制是否反转：一般设为true，主表作为主控方
//Lazy：是否延迟加载子表数据，主表上一般设为true，提高效率
[HasMany(typeof(Post), Table = "Posts", ColumnKey = "post_Employeesid", Cascade = ManyRelationCascadeEnum.AllDeleteOrphan, Inverse = true, Lazy = true,BatchSize=5,Fetch=FetchEnum.SubSelect)]
public IList Posts
{
get { return _posts; }
set { _posts = value; }
}

#region
public static void DeleteAll()
{
DeleteAll(typeof(Employees));
}
public static IList FindAll()
{
return (IList)FindAll(typeof(Employees));
}
public static Employees Find(int Employeesid)
{
return (Employees)FindByPrimaryKey(typeof(Employees), Employeesid);
}
#endregion
}

posts类
using System;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
using System.Collections;
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 Castle.ActiveRecord;
using Castle.ActiveRecord.Framework;
using Castle.ActiveRecord.Framework.Config;
using Castle.ActiveRecord.Framework.Internal;
using Castle.ActiveRecord.Framework.Scopes;
using Castle.ActiveRecord.Framework.Validators;
using Castle.ActiveRecord.Queries.Modifiers;
using Castle.ActiveRecord.Queries;

[ActiveRecord(Table = "Posts")]
public class Post : ActiveRecordBase
{
private int _post_id;
private String _post_title;
private String _post_contents;
private DateTime _post_created;
private Employees _employ;
public Post()
{
_post_created = DateTime.Now;
}

[PrimaryKey(PrimaryKeyType.Identity, Column = "post_id")]
public int post_id
{
get { return _post_id; }
set { _post_id = value; }
}
[Property(Column = "post_title")]
public String post_title
{
get { return _post_title; }
set { _post_title = value; }
}
[Property(Column = "post_contents", ColumnType = "StringClob")]
public String post_contents
{
get { return _post_contents; }
set { _post_contents = value; }
}
[Property(Column = "post_created")]
public DateTime post_created
{
get { return _post_created; }
set { _post_created = value; }
}

//子表没有inverse属性；
//Cascade：指定是否执行级联，子表指向主表的级联，一般也为None，因为一般子表删除一条数据，主表还是要保留的
//Column:子表关联字段，它是指向主表的字段
[BelongsTo(Column = "post_Employeesid", Cascade = CascadeEnum.None, Fetch = FetchEnum.SubSelect, Insert = true, Update = true, NotNull = true, OuterJoin = OuterJoinEnum.True)]
public Employees empploy
{
get { return _employ; }
set { _employ = value; }
}

public static void DeleteAll()
{
ActiveRecordBase.DeleteAll(typeof(Post));
}
public static Post[] FindAll()
{
return (Post[])ActiveRecordBase.FindAll(typeof(Post));
}
public static Post Find(int post_id)
{
return (Post)FindByPrimaryKey(typeof(Post), post_id);
}
}

使用
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Collections.Generic;
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 Castle;
using Castle.Core;
using Castle.ActiveRecord;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this.GridView1.DataSource = Employees.FindAll();
this.GridView1.DataBind();

//增加方法一,全部利用级联关系完成，子表数据不用进行save操作
using (TransactionScope tran = new TransactionScope())
{
Employees emp = new Employees();
emp.LogonName = "test";
emp.LastLogon = System.DateTime.Now;
try
{
IList ps = new List<Post>();
Post post = new Post();
post.post_title = "This is my post";
post.post_contents = "dsffsdf";
post.post_created = DateTime.Now;
post.empploy = emp;//绑定关系，一定要有
ps.Add(post);
emp.Posts = ps;
emp = (Employees)emp.SaveCopy();//保存并返回
tran.VoteCommit();
}
catch
{
tran.VoteRollBack();
}
}

//增加方法二，子表进行save操作，实际上这种就是没有全部利用级联的做法
using (TransactionScope tran = new TransactionScope())
{
try
{
Employees emp = new Employees();
emp.LogonName = "test";
emp.LastLogon = System.DateTime.Now;
emp = (Employees)emp.SaveCopy();//保存并返回
//创建Post对象
Post post = new Post();
post.post_title = "This is my post";
post.post_contents = "dsffsdf";
post.post_created = DateTime.Now;
post.empploy = emp;//绑定关系
post.Save();//子表数据写入
tran.VoteCommit();
}
catch
{
tran.VoteRollBack();
}
}

//修改数据
//using (TransactionScope tran = new TransactionScope())
//{
// Employees emp1 = Employees.Find(132);
// emp1.LogonName = "wo kao";
// foreach (Post p in emp1.Posts)//利用级联获取子表集合，并级联修改字表数据
// {
// p.post_title = "tttt1";
// }
// emp1.UpdateAndFlush();//更新主表数据，子表也会级联更新
//}

//删除主表数据，如果主表中设立了级联关系，子表数据也会删除；如果没有设，就不会删除
//using (TransactionScope tran = new TransactionScope())
//{
//Employees emp1 = Employees.Find(150);
//emp1.Delete();
//}

//方向关系，测试子表多主表关联，如果字表中设置了Cascade=All，那么主表数据也会删除，所以一般我们在子表中设置Cascade=None
//Post p = Post.Find(106);
//p.Delete();

}
}

单向关联和双向关联
One-Many和Many-One互为双向关系，实际上实现这种映射就会一定存在一种双向关系