ibatis返回HashMap结果类型与映射

<!-- 返回HashMap结果 类型-->
	<!-- 如果想返回JavaBean,只需将resultType设置为JavaBean的别名或全限定名 -->
	<!-- TypeAliasRegistry类初始化时注册了一些常用的别名，如果忘记了别名可以在这里面查看 -->
	<select id="selectBlogRetHashMap" parameterType="int" resultType="map">
		SELECT id AS "id", title AS "title", content AS "content" FROM Blog WHERE id = #{id}
	</select>

测试代码：

/**
	 * 测试返回HashMap
	 */
	@SuppressWarnings("unchecked")
	@Test
	public void testSelectBlogRetHashMap() {
		SqlSession session = sqlSessionFactory.openSession();
		HashMap<String,Object> blog = (HashMap<String,Object>) session.selectOne(
				"cn.enjoylife.BlogMapper.selectBlogRetHashMap", 15);
		session.close();
		System.out.println(blog.get("title"));
	}

ibatis高级映射：

表结构:

create table BLOG
(
  ID             NUMBER(20),
  TITLE          VARCHAR2(50),
  CONTENT        VARCHAR2(4000),
  BLOG_AUTHOR_ID NUMBER(20)
)
create table AUTHOR
(
  ID          NUMBER(20),
  AUTHOR_NAME VARCHAR2(50)
);
create table POSTS
(
  ID      NUMBER(20),
  SUBJECT VARCHAR2(50),
  BODY    VARCHAR2(4000),
  BLOG_ID NUMBER(20)
) 

bean信息：

package cn.enjoylife.domain;
import java.util.List;
public class Blog {
	private Integer id;
	private String title;
	private String content;
	private Author author;
	
	private List<Post> posts/*=new ArrayList<Post>()*/;
	
	public List<Post> getPosts() {
		return posts;
	}
	public void setPosts(List<Post> posts) {
		this.posts = posts;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}
	public String getContent() {
		return content;
	}
	public void setContent(String content) {
		this.content = content;
	}
	public Author getAuthor() {
		return author;
	}
	public void setAuthor(Author author) {
		this.author = author;
	}
	@Override
	public String toString() {
		return "Blog [content=" + content + ", id=" + id + ", title=" + title
				+ "]";
	}
}

package cn.enjoylife.domain;
public class Author {
	private Integer id;
	private String name;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Override
	public String toString() {
//		System.out.println("Author[id="+id+",name="+name+"]");
		return "Author[id="+id+",name="+name+"]";
	}
	
}

package cn.enjoylife.domain;
public class Post {
	private Integer id;
	private String subject;
	private String postContent;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getSubject() {
		return subject;
	}
	public void setSubject(String subject) {
		this.subject = subject;
	}
	public String getPostContent() {
		return postContent;
	}
	public void setPostContent(String postContent) {
		this.postContent = postContent;
	}
	@Override
	public String toString() {
		return "Post [postContent=" + postContent + ", id=" + id + ", subject=" + subject
				+ "]";
	}
	
	
}

Blog.xmll配置:

<!-- 高级结果映射 -->
	<!--
		 一对一关联 嵌套查询 应用select属性
		 1)id="selectBlogAndRelatedAuthor" 中的 blog_author_id 对应到
		 <association property="author" column="blog_author_id"/>中的column="blog_author_id"
		 2)我们执行selectBlogAndRelatedAuthor 1次之后，所产生的每条记录都要再进行一个查询来获取author信息（N），
		 这就是N+1问题，应该使用延迟加载的方式，否则这有可能产生致命的后果。
		 3)对于一对一关联,我设置了
		 	<settings>
		    	<setting name="lazyLoadingEnabled" value="true"/>
		    </settings>
		  却没有对Author进行延迟加载，不知为何。。。
	-->
	<resultMap id="blogResult" type="Blog" >
		<association property="author" column="blog_author_id"
		javaType="Author" select="selectAuthor"  />
	</resultMap>
	<select id="selectBlogAndRelatedAuthor" parameterType="int" resultMap="blogResult" >
		SELECT id,title,content,blog_author_id FROM blog WHERE id = #{id}
	</select>
	<select id="selectAuthor" parameterType="int" resultType="Author">
		SELECT id,author_name as "name" FROM author WHERE id = #{id}
	</select>
	<!--
		 一对一关联 嵌套结果 
	-->
	<resultMap id="blogResult2" type="Blog">
		<id property="id" column="id" />
		<result property="title" column="title"/>
		<association property="author" column="blog_author_id" 
			javaType="Author">
			<id property="id" column="author_id"/>
			<result property="name" column="author_name"/>
		</association>
	</resultMap>
	<select id="selectBlogAndRelatedAuthor2" parameterType="int" resultMap="blogResult2" >
		SELECT t.ID, t.TITLE, t.CONTENT, a.id as "author_id", a.author_name 
		  FROM blog t
		 INNER JOIN author a ON t.BLOG_AUTHOR_ID = a.ID
		                    AND t.ID = #{id}
	</select>
	
	<!--
		 一对多关联  嵌套查询，应用select属性 
		<collection property="posts" column="id" javaType="ArrayList" ofType="Post" 
			select="selectPosts"/>中的column指得是Post所对应表中的引用的主表中的主键id,
		注意：这个column指的是主表（Blog)中的id,我在这犯了个错，写为Post所对应表中的外键id,这是不对的，
		               应为所引用主表的主键id。
		property="posts" javaType="ArrayList" ofType="Post" 指属性posts为元素为Post的ArrayList类型   
		
		同样没有进行延迟加载，不知为何。。。
	-->
	<resultMap type="Blog" id="blogResult3" >
	    <id property="id" column="id"/>
	    <result property="title" column="title"/>
	    <result property="content" column="content"/>
		<collection property="posts" column="id" javaType="ArrayList" ofType="Post" 
			select="selectPosts"/>
	</resultMap>
	<select id="selectBlogAndRelatedPosts" parameterType="int" resultMap="blogResult3" >
		SELECT id, title, content FROM blog WHERE id = #{id}
	</select>
	<select id="selectPosts" parameterType="int" resultType="Post" >
		SELECT p.id,p.subject,p.body as "postContent" FROM posts p WHERE p.blog_id =#{id}
	</select>
	
	<!--
		 一对多关联  嵌套结果,在使用这种方式时，sql语句应该使用别名以保证不重复，如果不这样，可能
		出现结果不正确的现象，比如以下的post_id别名
	-->
	<resultMap type="Blog" id="blogResultVersion" >
		<id property="id" column="id" />
		<result property="title" column="title"/>
		<result property="content" column="content"/>
		<collection property="posts" javaType="ArrayList" ofType="Post" column="id">
			<id property="id" column="post_id"/>
			<result property="subject" column="subject"/>
			<result property="postContent" column="postContent"/>
		</collection>
	</resultMap>
	<select id="selectBlogAndRelatedPosts2" parameterType="int"  resultMap="blogResultVersion">
		SELECT t.id, t.title, t.content, p.id as "post_id", p.subject, p.BODY as "postContent"
		  FROM blog t
		 left outer JOIN posts p ON t.id = p.blog_id
		 WHERE t.ID = #{id}
	</select>

测试代码：

/**
	 * 测试一对一关联 嵌套查询
	 */
	@Test
	public void testSelectBlogAndRelatedAuthor() {
		SqlSession session = sqlSessionFactory.openSession();
		Blog blog = (Blog) session.selectOne(
				"cn.enjoylife.BlogMapper.selectBlogAndRelatedAuthor", 15);
		System.out.println(blog.toString());
		session.close();
		System.out.println(blog.getAuthor());
	}
	
	/**
	 * 测试一对一关联 嵌套结果
	 */
	@Test
	public void testSelectBlogAndRelatedAuthor2() {
		SqlSession session = sqlSessionFactory.openSession();
		Blog blog = (Blog) session.selectOne(
				"cn.enjoylife.BlogMapper.selectBlogAndRelatedAuthor2", 15);
		session.close();
		System.out.println(blog.toString());
		System.out.println(blog.getAuthor());
	}
	
	/**
	 * 测试一对多关联 嵌套查询
	 */
	@Test
	public void testSelectBlogAndRelatedPosts() throws Exception {
		SqlSession session = sqlSessionFactory.openSession();
		Blog blog = (Blog) session.selectOne(
				"cn.enjoylife.BlogMapper.selectBlogAndRelatedPosts", 15);
		System.out.println(blog.toString());
		session.close();
		System.out.println(blog.getPosts());
	}
	
	/**
	 * 测试一对多关联 嵌套结果
	 */
	@Test
	public void testSelectBlogAndRelatedPosts2() throws Exception {
		SqlSession session = sqlSessionFactory.openSession();
		Blog blog = (Blog) session.selectOne(
				"cn.enjoylife.BlogMapper.selectBlogAndRelatedPosts2", 15);
		session.close();
		System.out.println(blog.toString());
		System.out.println(blog.getPosts());
	}