IBatis.net ORM初体验
IBatis.net介绍
IBatis.net 是2001年发起的开源项目,它是一个轻量级的ORM框架,现在IBatisNET已经是属于Apache下的一个子项目了,最新版本是1.6.2.
.net项目下载地址:http://code.google.com/p/mybatisnet/
DataMapper:通过配置映射关系的xml业务对象与SQL语句和存储过程进行映射.
DataAcces:简单的说就是IBatis的数据访问层.
IBatis.net配置
主要要用到的几个配置文件:
providers.config 这个直接拷贝到根目录,该文件定义各种数据库的驱动,包括SqlServer, Oracle, MySQL, PostgreSQL, DB2 and OLEDB, ODBC 等。
sqlmap.config 就是非常核心的一个配置文件，主要配置了数据库访问字符串,settings设置,以及配置实体类和数据库表相关xml。
还有一个database.config 文件，它是配置一些在sqlmap中用到得参数.
然后需要引入两个DLL文件.
sqlmap.config文件代码:
<?xml version="1.0" encoding="utf-8"?>
<sqlMapConfig xmlns="http://ibatis.apache.org/dataMapper" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<!--<providers resource="database.config" />--><settings>
<setting useStatementNamespaces="true"/>
<setting cacheModelsEnabled="true"/>
</settings>
<providers resource="providers.config" />
<database>
<!-- Optional ( default ) --><provider name="sqlServer2.0"/>
<dataSource name="iBatisNet" connectionString="Server=.; User ID=sa;Password=sa;Database=TestDB;Persist Security Info=True"/>
</database>
<sqlMaps>
<sqlMap resource="Maps/Account.xml"/>
</sqlMaps>
</sqlMapConfig>
useStatementNamespaces:是否启用命名空间
cacheModelsEnabled:是否缓存数据
<providers resource="providers.config" /> 引入数据库驱动文件
sqlMaps 节点就是配置一些sql语句以及实体映射的xml文件.
IBatis.net实战
现在让我们来做一个Demo
我用的是Sqlserver2005 ,新建一个数据表
在Vs2010下新建项目IBatisDemo
项目结构如下
IBatisDemo.Dao 提供一个统一的Mapper访问接口,
IBatisDemo.Model 数据实体
IBatisDemo.Service 数据操作
因为是做Demo没有对整体架构做过多的细节设置.
首先配置网站根目录下的Maps/Account.xml如下：
<?xml version="1.0" encoding="utf-8" ?>
<sqlMap namespace="Account" xmlns="http://ibatis.apache.org/mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<alias>
<!-- alias:取别名 assembly:表示类所在的文件 type:表示该类的完整的名称 --><typeAlias alias="Account" assembly="IBatisDemo.Model.dll" type="IBatisDemo.Model.Accounts" />
</alias>
<resultMaps>
<resultMap id="Account-result" class="Account">
<result property="Id" column="id"/>
<result property="Item" column="Item"/>
<result property="Year" column="Year"/>
<result property="Month" column="Month"/>
<result property="Day" column="Day"/>
<result property="CreateOn" column="CreateOn"/>
<result property="Level" column="Level"/>
</resultMap>
</resultMaps>
<statements>
<select id="sql_selectByid" resultMap="Account-result">
select * from Accounts
<dynamic prepend="where">
<isParameterPresent property="id" prepend="">
[id] = #id#
</isParameterPresent>
</dynamic>
</select>
<select id="sql_selectAll" resultMap="Account-result">
select * from Accounts
</select>
<insert id="sql_InsertOne" parameterClass="Account">
insert into Accounts (Item,Money,Year,Month,Day,CreateOn,Level)
values
(#Item#,
#Money#,
#Year#,
#Month#,
#Day#,
#CreateOn#,
#Level#
)
<selectKey type="post" resultClass="int" property="Id">
SELECT CAST(@@IDENTITY as int) as Id
</selectKey>
</insert>
</statements>
</sqlMap>
说明:
statements 节点：
在这些容器标签中有一些常用的属性如下所示
resultMap和resultclass对比:
1、resultMap属于直接映射，可以把结果集中的数据库字段与实体类中的属性一一对应，这样通过select语句得到的结果就会准确的对上号
2、resultclass属于隐身映射，虽然你指定resultclass=“”，具体某一个类，但是select语句得到的结果是一条实力记录，但如果数据库字段与类的属性名字不一致，这个时候就会出现映射错误，有一种方式可以解决就是在写select语句时，给每个字段用as运算符取名字与属性一样：例如：select realname as name...其中realname是字段列名，name是属性字段名
3、resultmap比resultclass性能要高。尽量使用resultmap
insert标签下的selectKey 是表示返回刚插入数据的主键id，具体说明如下
<!-- 为了使insert操作能够返回插入记录的id，必须为insert写一个selectKey –><!-- 下面是sqlserver写法--><selectKey type="post" resultClass="int" property="Id">
SELECT CAST(@@IDENTITY as int) as Id
</selectKey>
<!-- 下面是针对Oracle的写法,Oracle没有autoincrement，而是用触发器实现的 CURRVAL是在触发器中定义的--><!--<insert id="insertRemark" parameterClass="RemarkInfo"> insert into SGS_REMARK(REMARK) values(#remark#) <selectKey resultClass="int" keyProperty="id" > SELECT S_SGS_REMARK.CURRVAL AS ID FROM DUAL </selectKey> </insert>--><!-- 下面是针对MySQL的写法 --><!-- <selectKey resultClass="int" keyProperty="id" > SELECT @@IDENTITY AS id </selectKey> -->
Account.xml配置完成 .建实体类:
using System;using System.Collections.Generic;using System.Text;namespace IBatisDemo.Model{public class Accounts
{public int Id { get; set; }
public string Item { get; set; }
public float Money { get; set; }
public int Month { get; set; }
public int Year { get; set; }
public int Day { get; set; }
public DateTime CreateOn { get; set; }public string Level { get; set; }
}
}
Mapper.cs 获取Mapper的对象类:
using System;using System.Collections.Generic;using System.Linq;using System.Text;using IBatisNet.DataMapper;using IBatisNet.Common.Utilities;using IBatisNet.DataMapper.Configuration;namespace IBatisDemo.Dao{public class Mapper
{private static volatile ISqlMapper _mapper = null;
protected static void Configure(object obj)
{ _mapper = null;}
protected static void InitMapper()
{ ConfigureHandler handler = new ConfigureHandler(Configure); DomSqlMapBuilder builder = new DomSqlMapBuilder();_mapper = builder.ConfigureAndWatch(handler);
}
public static ISqlMapper Instance()
{if (_mapper == null)
{lock (typeof(SqlMapper))
{if (_mapper == null) // double-check
{InitMapper();
}
}
}
return _mapper;}
public static ISqlMapper Get()
{ return Instance();}
/// <summary> /// RealMarket Mapper /// </summary>public static ISqlMapper GetMaper
{get
{if (_mapper == null)
{lock (typeof(ISqlMapper))
{if (_mapper == null)
{ ConfigureHandler hander = new ConfigureHandler(Configure); DomSqlMapBuilder builder = new DomSqlMapBuilder(); _mapper = builder.ConfigureAndWatch("sqlmap.config", hander);}
}
}
return _mapper;}
}
}
}
然后再Service里面建立AccountService.cs 数据访问
using System;using System.Collections.Generic;using System.Text;using System.Reflection;using System.IO;using IBatisDemo.Model;using System.Data.SqlClient;using IBatisDemo.Dao;namespace IBatisDemo.Service{public class AccountService
{public int TestInsertOne(Accounts account)
{ Object obj =Mapper.GetMaper.Insert("Account.sql_InsertOne", account);return (int)obj;
}
public Accounts GetAccount(int id)
{return (Accounts)Mapper.GetMaper.QueryForObject("Account.sql_selectByid", id);
}
public IList<Accounts> GetAccountList() {return Mapper.GetMaper.QueryForList<Accounts>("Account.sql_selectAll", null);
}
}
}
这里要注意命名空间.
在Default.aspx页面上调用Service
protected void Button1_Click(object sender, EventArgs e)
{ Accounts account = new Accounts();account.Id =-1;
account.CreateOn = DateTime.Now;
account.Day = 12;
account.Item = "小刚1"; account.Level = "无";account.Money = 56;
account.Month = 6;
account.Year = 2011;
AccountService service = new AccountService();service.TestInsertOne(account);
}
protected void Button3_Click(object sender, EventArgs e)
{ AccountService service = new AccountService();IList<Accounts> accounts = service.GetAccountList();
this.GridView1.DataSource = accounts; this.GridView1.DataBind();}
protected void Button2_Click(object sender, EventArgs e)
{ AccountService service = new AccountService();Accounts account = service.GetAccount(2);
}
运行效果:
写起来比较简单,配置起来还是很麻烦的.也许是第一次接触吧。比较简单，就不提供源码咯.
后续再带来更深入的用法..