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[Java教程]MyBatis入门(二)


一、创建数据库表

1.1、创建数据表同时插入数据

 

/*SQLyog Enterprise v12.09 (64 bit)MySQL - 5.6.27-log : Database - mybatis**********************************************************************//*!40101 SET NAMES utf8 */;/*!40101 SET SQL_MODE=''*/;/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;CREATE DATABASE /*!32312 IF NOT EXISTS*/`mybatis` /*!40100 DEFAULT CHARACTER SET utf8 */;USE `mybatis`;/*Table structure for table `author` */DROP TABLE IF EXISTS `author`;CREATE TABLE `author` ( `author_id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '作者ID主键', `author_username` varchar(30) NOT NULL COMMENT '作者用户名', `author_password` varchar(32) NOT NULL COMMENT '作者密码', `author_email` varchar(50) NOT NULL COMMENT '作者邮箱', `author_bio` varchar(1000) DEFAULT '这家伙很赖,什么也没留下' COMMENT '作者简介', `register_time` datetime DEFAULT CURRENT_TIMESTAMP COMMENT '注册时间', PRIMARY KEY (`author_id`)) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;/*Data for the table `author` */

insert into `author`(`author_id`,`author_username`,`author_password`,`author_email`,`author_bio`,`register_time`) values (1,'张三','123456','123@qq.com','张三是个新手,刚开始注册','2015-10-29 10:23:59'),(2,'李四','123asf','lisi@163.com','魂牵梦萦 ','2015-10-29 10:24:29'),(3,'王五','dfsd342','ww@sina.com','康熙王朝','2015-10-29 10:25:23'),(4,'赵六','123098sdfa','zhaoliu@qq.com','花午骨','2015-10-29 10:26:09'),(5,'钱七','zxasqw','qianqi@qq.com','这家伙很赖,什么也没留下','2015-10-29 10:27:04'),(6,'张三丰','123456','zhangsf@qq.com','这家伙很赖,什么也没留下','2015-10-29 11:48:00'),(7,'张无忌','qwertyuiop','wuji@163.com','这家伙很赖,什么也没留下','2015-10-29 11:48:24');

/*Table structure for table `blog` */DROP TABLE IF EXISTS `blog`;CREATE TABLE `blog` ( `blog_id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT 'BlogId主键', `blog_title` varchar(255) NOT NULL COMMENT 'blog标题', `author_id` int(11) unsigned NOT NULL COMMENT '作者ID外键', PRIMARY KEY (`blog_id`), KEY `fk_author_id` (`author_id`), CONSTRAINT `fk_author_id` FOREIGN KEY (`author_id`) REFERENCES `author` (`author_id`)) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;/*Data for the table `blog` */insert into `blog`(`blog_id`,`blog_title`,`author_id`) values (1,'小张的Blog',1),(2,'小李',2),(3,'王五不是人',3),(4,'赵地人',4),(5,'钱钱钱',5);/*Table structure for table `posts` */DROP TABLE IF EXISTS `posts`;CREATE TABLE `posts` ( `post_id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '文章主键ID', `post_subject` varchar(255) NOT NULL COMMENT '文章主题,标题', `post_body` text NOT NULL COMMENT '文章内容最大3000个字符', `blog_id` int(11) unsigned NOT NULL COMMENT 'Blog主键做外键', `createtime` datetime DEFAULT CURRENT_TIMESTAMP COMMENT '文章创建时间', PRIMARY KEY (`post_id`), KEY `fk_blog_id` (`blog_id`), CONSTRAINT `fk_blog_id` FOREIGN KEY (`blog_id`) REFERENCES `blog` (`blog_id`)) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8mb4;/*Data for the table `posts` */insert into `posts`(`post_id`,`post_subject`,`post_body`,`blog_id`,`createtime`) values (1,'Mybatis入门一','什么是 MyBatis ?\r\nMyBatis 是支持定制化 SQL、存储过程以及高级映射的优秀的持久层框架。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以对配置和原生Map使用简单的 ',1,'2015-10-29 10:32:21'),(2,'Mybatis入门二','要使用 MyBatis, 只需将 mybatis-x.x.x.jar 文件置于 classpath 中即可。',1,'2015-10-29 10:32:52'),(3,'Oracle学习','Oracle Database,又名Oracle RDBMS,或简称Oracle。是甲骨文公司的一款关系数据库管理系统',2,'2015-10-29 10:33:26'),(4,'JAVA学习一','Java是由Sun Microsystems公司于1995年5月推出的Java面向对象程序设计语言和Java平台的总称',3,'2015-10-29 10:34:17'),(5,'PL/SQL','PL/SQL也是一种程序语言,叫做过程化SQL语言(Procedural Language/SQL)。PL/SQL是Oracle数据库对SQL语句的扩展',4,'2015-10-29 10:37:52'),(6,'CSS标签选择器','标签选择器\r\nID选择器\r\n类选择器\r\n特殊选择器',5,'2015-10-29 10:39:44'),(7,'javascript','js:是前端脚本语言',2,'2015-10-29 10:40:18');/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

 

 

 

二、创建项目

2.1、创建项目并加入jar包

 

2.2、创建实体类以author为例

 

package com.pb.mybatis.po;import java.util.Date;/** * * @Title: Author.java* @Package com.pb.mybatis.po* @ClassName Author* @Description: TODO(Blog作者类)* @author 刘楠 * @date 2015-10-29 上午9:27:53* @version V1.0 */public class Author {  //作者ID  private int authorId;    //作者用户名  private String authorUserName;    //作者密码  private String authorPassword;    //作者邮箱  private String authorEmail;    //作者介绍  private int authorBio;    //注册时间  private Date registerTime;  /**   * @return the authorId   */  public int getAuthorId() {    return authorId;  }  /**   * @param authorId the authorId to set   */  public void setAuthorId(int authorId) {    this.authorId = authorId;  }  /**   * @return the authorUserName   */  public String getAuthorUserName() {    return authorUserName;  }  /**   * @param authorUserName the authorUserName to set   */  public void setAuthorUserName(String authorUserName) {    this.authorUserName = authorUserName;  }  /**   * @return the authorPassword   */  public String getAuthorPassword() {    return authorPassword;  }  /**   * @param authorPassword the authorPassword to set   */  public void setAuthorPassword(String authorPassword) {    this.authorPassword = authorPassword;  }  /**   * @return the authorEmail   */  public String getAuthorEmail() {    return authorEmail;  }  /**   * @param authorEmail the authorEmail to set   */  public void setAuthorEmail(String authorEmail) {    this.authorEmail = authorEmail;  }  /**   * @return the authorBio   */  public int getAuthorBio() {    return authorBio;  }  /**   * @param authorBio the authorBio to set   */  public void setAuthorBio(int authorBio) {    this.authorBio = authorBio;  }  /**   * @return the registerTime   */  public Date getRegisterTime() {    return registerTime;  }  /**   * @param registerTime the registerTime to set   */  public void setRegisterTime(Date registerTime) {    this.registerTime = registerTime;  }  /** (non Javadoc)     * <p>Title: toString</p>     * <p>Description:重写toString方法 </p>     * @return     * @see java.lang.Object#toString()   */  @Override  public String toString() {    return "Author [authorId=" + authorId + ", authorUserName="        + authorUserName + ", authorPassword=" + authorPassword        + ", authorEmail=" + authorEmail + ", authorBio=" + authorBio        + ", registerTime=" + registerTime + "]";  }      }

 

 

2.3、创建mybatis配置文件

 

<??><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><properties resource="db.properties" /><typeAliases><!--使用默认别名 --><package name="com.pb.mybatis.po"/></typeAliases><environments default="development"><environment id="development">  <transactionManager type="JDBC"/>  <dataSource type="POOLED">    <property name="driver" value="${jdbc.driver}"/>    <property name="url" value="${jdbc.url}"/>    <property name="username" value="${jdbc.username}"/>    <property name="password" value="${jdbc.password}"/>  </dataSource></environment></environments><mappers><!-- 加载映射 --><package name="com.pb.mybatis.mapper"/></mappers></configuration>

 

2.4、创建实体类对象的接口以author为例

 

/***/package com.pb.mybatis.mapper;import java.util.List;import com.pb.mybatis.po.Author;/**  * @Title: AuthorMapper.java * @Package com.pb.mybatis.mapper * @ClassName AuthorMapper * @Description: TODO(作者接口) * @author 刘楠 * @date 2015-10-29 上午11:13:10 * @version V1.0  */public interface AuthorMapper {    /**   *   * @Title: findById     * @Description: TODO(根据查找一个用户)     * @param id   * @return Author   */  public Author findAuthorById(int authorId);    /**   *   * @Title: findByName     * @Description: TODO(根据用户名,模糊查询)     * @param name   * @return List<Author>   */  public List<Author> findAuthorByName(String name);    /**   *   * @Title: addAuthor     * @Description: TODO(添加作者)     * @param author   * @return int   */  public int addAuthor(Author author);    /**   *   * @Title: updateAuthor     * @Description: TODO(修改用户)     * @param authro   * @return int   */  public int updateAuthor(Author authro);    /**   *   * @Title: deleteAturho     * @Description: TODO(根据ID删除作者)     * @param id   * @return int   */  public int deleteAuthor(int authorId);}

 

 

2.5、创建接口对应的mapper.xm以author为例

 

<??><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.pb.mybatis.mapper.AuthorMapper"><!--使用resultMap映射 type使用别名,--><resultMap type="Author" id="authorResultMap"><!--主键 --><id property="authorId" column="author_id"/><!--普通属性与表中的字段对应 --><result property="authorUserName" column="author_username"/><result property="authorPassword" column="author_password"/><result property="authorEmail" column="author_email"/><result property="authorBio" column="author_bio"/><result property="registerTime" column="register_time"/></resultMap><!--根据查找一个用户 --><select id="findAuthorById" parameterType="int" resultMap="authorResultMap">SELECT * FROM authorWHERE author_id=#{authorId}</select><!-- 根据用户名,模糊查询 --><select id="findAuthorByName" parameterType="String" resultMap="authorResultMap">SELECT * FROM authorWHERE author_username LIKE "%"#{name}"%"</select><!--添加用户  useGeneratedKeys="true" 使用数据库自增序列 keyProperty="authorId"将主键返回#号中写PO类中的属性--><insert id="addAuthor" parameterType="Author" useGeneratedKeys="true" keyProperty="authorId">INSERT INTO author(author_username,author_password,author_email,author_bio,register_time) VALUES(#{authorUserName},#{authorPassword},#{authorEmail},#{authorBio},#{registerTime})</insert><!--修改用户 --><update id="updateAuthor" parameterType="Author">update author set author_username=#{authorUserName},author_password=#{authorPassword},author_email=#{authorEmail},author_bio=#{authorBio},register_time=#{registerTime}where author_id=#{authorId}</update><!--删除用户 根据ID--><delete id="deleteAuthor" parameterType="int">delete from authorwhere author_id=#{authorId}</delete></mapper>

 

 

 

 

 

三、简单实现增删改查

3.1、测试类以author为例

 

/***/package com.pb.mybatis.mapper;import java.io.InputStream;import java.util.Date;import java.util.List;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import org.junit.Before;import org.junit.Test;import com.pb.mybatis.po.Author;/**  * @Title: AuthorMapperTest.java * @Package com.pb.mybatis.mapper * @ClassName AuthorMapperTest * @Description: TODO(测试) * @author 刘楠 * @date 2015-10-29 上午11:57:21 * @version V1.0  */public class AuthorMapperTest {    private SqlSessionFactory sqlSessionFactory;    /**   *   * @Title: setUp     * @Description: TODO(在每个方法前执行的方法)     * @throws Exception void   */  @Before  public void setUp() throws Exception {    String resource="configuration.;    InputStream in=Resources.getResourceAsStream(resource);    //获取会话工厂    sqlSessionFactory=new SqlSessionFactoryBuilder().build(in);  }  /**   *   * @Title: testFindAuthorById     * @Description: TODO(根据查找一个用户)   void   */  @Test  public void testFindAuthorById() {    //获取会话    SqlSession sqlSession=sqlSessionFactory.openSession();    //Mapper接口    AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);    //调用方法    Author author=authorMapper.findAuthorById(2);    System.out.println(author);    //关闭会话    sqlSession.close();  }  /**   *   * @Title: testFindAuthorByName     * @Description: TODO(根据用户名,模糊查询)   void   */  @Test  public void testFindAuthorByName() {    //获取会话        SqlSession sqlSession=sqlSessionFactory.openSession();        //Mapper接口        AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);        //调用方法        List<Author> authors=authorMapper.findAuthorByName("张");        System.out.println(authors);        //关闭会话        sqlSession.close();        for(Author a:authors){          System.out.println(a.toString());        }  }  /**   *   * @Title: testAddAuthor     * @Description: TODO(添加作者)   void   */  @Test  public void testAddAuthor() {    //获取会话    SqlSession sqlSession=sqlSessionFactory.openSession();    //Mapper接口    AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);    //调用方法    Author author=new Author();    author.setAuthorUserName("不知道");    author.setAuthorPassword("1234567890");    author.setAuthorEmail("123456@qq.com");    author.setAuthorBio("知道是个什么");    author.setRegisterTime(new Date());    int num=authorMapper.addAuthor(author);    System.out.println("num="+num);    System.out.println("authorId="+author.getAuthorId());    sqlSession.commit();    //关闭会话    sqlSession.close();      }  /**   *   * @Title: testUpdateAuthor     * @Description: TODO(修改用户)   void   */  @Test  public void testUpdateAuthor() {    //获取会话        SqlSession sqlSession=sqlSessionFactory.openSession();        //Mapper接口        AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);        //调用方法        Author author=authorMapper.findAuthorById(8);        author.setAuthorUserName("知道了");        author.setAuthorPassword("456789");        author.setAuthorEmail("456789@qq.com");        author.setAuthorBio("哈哈哈哈哈雅虎");        author.setRegisterTime(new Date());        int num=authorMapper.updateAuthor(author);        System.out.println("num="+num);        System.out.println("authorId="+author.getAuthorId());        sqlSession.commit();        //关闭会话        sqlSession.close();          }  /**   *   * @Title: testDeleteAuthor     * @Description: TODO(根据ID删除作者)   void   */  @Test  public void testDeleteAuthor() {    //获取会话    SqlSession sqlSession=sqlSessionFactory.openSession();    //Mapper接口    AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);    //调用方法        int num=authorMapper.deleteAuthor(10);    System.out.println("num="+num);      sqlSession.commit();    //关闭会话    sqlSession.close();  }}

 

 

四、实现一对一

4.1、建立Blog类

 

package com.pb.mybatis.po;/**  * @Title: Blog.java * @Package com.pb.mybatis.po * @ClassName Blog * @Description: TODO(博客) * @author 刘楠 * @date 2015-10-29 上午9:32:56 * @version V1.0  */public class Blog {  //博客ID  private int blogId;    //标题  private String blogTitle;    //博客作者  private Author author;  /**   * @return the blogId   */  public int getBlogId() {    return blogId;  }  /**   * @param blogId the blogId to set   */  public void setBlogId(int blogId) {    this.blogId = blogId;  }  /**   * @return the blogTitle   */  public String getBlogTitle() {    return blogTitle;  }  /**   * @param blogTitle the blogTitle to set   */  public void setBlogTitle(String blogTitle) {    this.blogTitle = blogTitle;  }  /**   * @return the author   */  public Author getAuthor() {    return author;  }  /**   * @param author the author to set   */  public void setAuthor(Author author) {    this.author = author;  }  /** (non Javadoc)     * <p>Title: toString</p>     * <p>Description: 重写toString方法</p>     * @return     * @see java.lang.Object#toString()   */  @Override  public String toString() {    return "Blog [blogId=" + blogId + ", blogTitle=" + blogTitle        + ", author=" + author + "]";  }    }

 

4.2、建立BlogMapper接口

 

/***/package com.pb.mybatis.mapper;import java.util.List;import com.pb.mybatis.po.Author;import com.pb.mybatis.po.Blog;/**  * @Title: BlogMapper.java * @Package com.pb.mybatis.mapper * @ClassName BlogMapper * @Description: TODO(用一句话描述该文件做什么) * @author 刘楠 * @date 2015-10-29 上午11:13:21 * @version V1.0  */public interface BlogMapper {  /**   *   * @Title: findBlogById     * @Description: TODO(根据ID查找BLOG)     * @param id   * @return Blog   */  public Blog findBlogById(int id);    /**   *   * @Title: findByName     * @Description: TODO(根据博客名查找)     * @param name   * @return List<Blog>   */  public List<Blog> findBlogByName(String blogTitle);    /**   *   * @Title: addBlog     * @Description: TODO(添加博客)     * @param blog   * @return int   */  public int addBlog(Blog blog);      /**   *   * @Title: updateBlog     * @Description: TODO(修改博客)     * @param blog   * @return int   */  public int updateBlog(Blog blog);    /**   *   * @Title: deleteBlog     * @Description: TODO(删除博客)     * @param id   * @return int   */  public int deleteBlog(int id);}

 

4.3、建立mapper.

 

<??><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.pb.mybatis.mapper.BlogMapper"><!--使用ResultMap --><resultMap type="Blog" id="blogResultMap"><!--主键 --><id property="blogId" column="blog_id"/><!--标题 --><result property="blogTitle" column="blog_title"/><!--一对一关联  第一种--><association property="author" resultMap="authorResultMap"/><!-- 第二种把作者类再映射在一个resultMap中<association property="author" resultMap="authorResultMap"><id property="authorId" column="author_id"/>普通属性与表中的字段对应 <result property="authorUserName" column="author_username"/><result property="authorPassword" column="author_password"/><result property="authorEmail" column="author_email"/><result property="authorBio" column="author_bio"/><result property="registerTime" column="register_time"/></association> --></resultMap><!--使用resultMap映射 type使用别名,单独使用Author关联--><resultMap type="Author" id="authorResultMap"><!--主键 --><id property="authorId" column="author_id"/><!--普通属性与表中的字段对应 --><result property="authorUserName" column="author_username"/><result property="authorPassword" column="author_password"/><result property="authorEmail" column="author_email"/><result property="authorBio" column="author_bio"/><result property="registerTime" column="register_time"/></resultMap><!-- 根据ID查询--><select id="findBlogById" parameterType="int" resultMap="blogResultMap">SELECT blog.blog_id,blog.blog_title,author.author_id,author.author_username,author.author_password,author.author_email,author.author_bio,author.register_timeFROM blog,author  WHERE blog.author_id=author.author_idAND blog.blog_id=#{blogId}</select><!-- 根据名字查询 --><select id="findBlogByName" parameterType="String" resultMap="blogResultMap">SELECT blog.blog_id,blog.blog_title,author.author_id,author.author_username,author.author_password,author.author_email,author.author_bio,author.register_timeFROM blog,author  WHERE blog.author_id=author.author_idAND blog_title LIKE "%"#{blogTitle}"%"</select><!-- 添加Blog --><insert id="addBlog" parameterType="Blog" useGeneratedKeys="true" keyProperty="blogId">INSERT INTO blog(blog_title,author_id)VALUES(#{blogTitle},#{author.authorId})</insert><!--修改 --><update id="updateBlog" parameterType="Blog">UPDATE blog SET blog_title=#{blogTitle},author_id=#{author.authorId}WHERE blog_id=#{blogId}</update><!--删除 --><delete id="deleteBlog" parameterType="int">delete from blog where blog_id=#{blogId}</delete></mapper>

 

4.1、测试类

 

package com.pb.mybatis.mapper;import static org.junit.Assert.*;import java.io.InputStream;import java.util.List;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import org.junit.Before;import org.junit.Test;import com.pb.mybatis.po.Author;import com.pb.mybatis.po.Blog;/**  * @Title: BlogMapperTest.java * @Package com.pb.mybatis.mapper * @ClassName BlogMapperTest * @Description: TODO(用一句话描述该文件做什么) * @author 刘楠 * @date 2015-10-29 下午3:12:52 * @version V1.0  */public class BlogMapperTest {  private SqlSessionFactory sqlSessionFactory;    @Before  public void setUp() throws Exception {    String resource="configuration.;    InputStream in=Resources.getResourceAsStream(resource);    //获取会话工厂    sqlSessionFactory=new SqlSessionFactoryBuilder().build(in);  }  /**   * Test method for {@link com.pb.mybatis.mapper.BlogMapper#findBlogById(int)}.   */  @Test  public void testFindBlogById() {    //获取会话        SqlSession sqlSession=sqlSessionFactory.openSession();        //Mapper接口        BlogMapper blogMapper=sqlSession.getMapper(BlogMapper.class);        //调用方法        Blog blog=blogMapper.findBlogById(2);        System.out.println(blog);        //关闭会话        sqlSession.close();  }  /**   * Test method for {@link com.pb.mybatis.mapper.BlogMapper#findBlogByName(java.lang.String)}.   */  @Test  public void testFindBlogByName() {    //获取会话    SqlSession sqlSession=sqlSessionFactory.openSession();    //Mapper接口    BlogMapper blogMapper=sqlSession.getMapper(BlogMapper.class);    //调用方法    List<Blog> blogs=blogMapper.findBlogByName("小");    System.out.println(blogs);    //关闭会话    sqlSession.close();  }  /**   * Test method for {@link com.pb.mybatis.mapper.BlogMapper#addBlog(com.pb.mybatis.po.Blog)}.   */  @Test  public void testAddBlog() {    //获取会话        SqlSession sqlSession=sqlSessionFactory.openSession();        //Mapper接口        BlogMapper blogMapper=sqlSession.getMapper(BlogMapper.class);        Blog blog=new Blog();        blog.setBlogTitle("倚天屠龙记");        AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);        //调用方法        Author author=authorMapper.findAuthorById(2);        blog.setAuthor(author);        int num=blogMapper.addBlog(blog);        System.out.println("num="+num);        System.out.println(blog.getBlogId());        sqlSession.commit();        sqlSession.close();  }  /**   * Test method for {@link com.pb.mybatis.mapper.BlogMapper#updateBlog(com.pb.mybatis.po.Blog)}.   */  @Test  public void testUpdateBlog() {    //获取会话    SqlSession sqlSession=sqlSessionFactory.openSession();    //Mapper接口    BlogMapper blogMapper=sqlSession.getMapper(BlogMapper.class);    //调用方法    Blog blog=blogMapper.findBlogById(8);    blog.setBlogTitle("笑傲江湖");    Author author=blog.getAuthor();    author.setAuthorUserName("金庸");    AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);    int authorNum=authorMapper.updateAuthor(author);    int num=blogMapper.updateBlog(blog);    System.out.println("authorNum="+authorNum);    System.out.println("num="+num);    sqlSession.commit();    //关闭会话    sqlSession.close();  }  /**   * Test method for {@link com.pb.mybatis.mapper.BlogMapper#deleteBlog(int)}.   */  @Test  public void testDeleteBlog() {    //获取会话        SqlSession sqlSession=sqlSessionFactory.openSession();        //Mapper接口        BlogMapper blogMapper=sqlSession.getMapper(BlogMapper.class);        int num=blogMapper.deleteBlog(11);        System.out.println("num="+num);        sqlSession.commit();        sqlSession.close();    }}

 

 

 

五、一对多

5.1、建立Posts类

 

package com.pb.mybatis.po;import java.util.Date;/**  * @Title: Posts.java * @Package com.pb.mybatis.po * @ClassName Posts * @Description: TODO(Blog文章) * @author 刘楠 * @date 2015-10-29 上午9:31:22 * @version V1.0  */public class Posts {  //文章ID  private int postId;    //文件主题  private String postSubject;    //主体内容  private String postBody;  //文章建立时间  private Date createTime;      /**   * @return the postId   */  public int getPostId() {    return postId;  }  /**   * @param postId the postId to set   */  public void setPostId(int postId) {    this.postId = postId;  }  /**   * @return the postSubject   */  public String getPostSubject() {    return postSubject;  }  /**   * @param postSubject the postSubject to set   */  public void setPostSubject(String postSubject) {    this.postSubject = postSubject;  }  /**   * @return the postBody   */  public String getPostBody() {    return postBody;  }  /**   * @param postBody the postBody to set   */  public void setPostBody(String postBody) {    this.postBody = postBody;  }  /**   * @return the createTime   */  public Date getCreateTime() {    return createTime;  }  /**   * @param createTime the createTime to set   */  public void setCreateTime(Date createTime) {    this.createTime = createTime;  }  /** (non Javadoc)     * <p>Title: toString</p>     * <p>Description:重写toString方法</p>     * @return     * @see java.lang.Object#toString()   */  @Override  public String toString() {    return "Posts [postId=" + postId + ", postSubject=" + postSubject        + ", postBody=" + postBody +", createTime="        + createTime + "]";  }        }

 

5.2、在blog类中添加List

 

package com.pb.mybatis.po;import java.util.List;/**  * @Title: Blog.java * @Package com.pb.mybatis.po * @ClassName Blog * @Description: TODO(博客) * @author 刘楠 * @date 2015-10-29 上午9:32:56 * @version V1.0  */public class Blog {  //博客ID  private int blogId;    //标题  private String blogTitle;    //博客作者  private Author author;    //文章List  private List<Posts> posts;  /**   * @return the blogId   */  public int getBlogId() {    return blogId;  }  /**   * @param blogId the blogId to set   */  public void setBlogId(int blogId) {    this.blogId = blogId;  }  /**   * @return the blogTitle   */  public String getBlogTitle() {    return blogTitle;  }  /**   * @param blogTitle the blogTitle to set   */  public void setBlogTitle(String blogTitle) {    this.blogTitle = blogTitle;  }  /**   * @return the author   */  public Author getAuthor() {    return author;  }  /**   * @param author the author to set   */  public void setAuthor(Author author) {    this.author = author;  }  /**   * @return the posts   */  public List<Posts> getPosts() {    return posts;  }  /**   * @param posts the posts to set   */  public void setPosts(List<Posts> posts) {    this.posts = posts;  }  /** (non Javadoc)     * <p>Title: toString</p>     * <p>Description: </p>     * @return     * @see java.lang.Object#toString()   */  @Override  public String toString() {    return "Blog [blogId=" + blogId + ", blogTitle=" + blogTitle        + ", author=" + author + ", posts=" + posts + "]";  }      }

 

5.3、修改blogMapper.

 

<??><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.pb.mybatis.mapper.BlogMapper"><!--使用ResultMap --><resultMap type="Blog" id="blogResultMap"><!--主键 --><id property="blogId" column="blog_id"/><!--标题 --><result property="blogTitle" column="blog_title"/><!--一对一关联  第一种--><association property="author" resultMap="authorResultMap"/><!--一对多关联 --><collection property="posts" resultMap="postsResultMap" ofType="Posts"/><!-- 第二种把作者类再映射在一个resultMap中<association property="author" resultMap="authorResultMap"><id property="authorId" column="author_id"/>普通属性与表中的字段对应 <result property="authorUserName" column="author_username"/><result property="authorPassword" column="author_password"/><result property="authorEmail" column="author_email"/><result property="authorBio" column="author_bio"/><result property="registerTime" column="register_time"/></association> --></resultMap><!--文章Map --><resultMap type="Posts" id="postsResultMap"><id property="postId" column="post_id"/><result property="postSubject" column="post_subject"/><result property="postBody" column="post_body"/><result property="createTime" column="createtime"/></resultMap><!--使用resultMap映射 type使用别名,单独使用Author关联--><resultMap type="Author" id="authorResultMap"><!--主键 --><id property="authorId" column="author_id"/><!--普通属性与表中的字段对应 --><result property="authorUserName" column="author_username"/><result property="authorPassword" column="author_password"/><result property="authorEmail" column="author_email"/><result property="authorBio" column="author_bio"/><result property="registerTime" column="register_time"/></resultMap><!-- 根据ID查询--><select id="findBlogById" parameterType="int" resultMap="blogResultMap">SELECT blog.blog_id,blog.blog_title,author.author_id,author.author_username,author.author_password,author.author_email,author.author_bio,author.register_time,posts.post_id,posts.post_subject,posts.post_body,posts.createtime,posts.blog_idFROM blog,author,posts  WHERE blog.author_id=author.author_idAND blog.blog_id=posts.blog_idAND blog.blog_id=#{blogId}</select><!-- 根据名字查询 --><select id="findBlogByName" parameterType="String" resultMap="blogResultMap">SELECT blog.blog_id,blog.blog_title,author.author_id,author.author_username,author.author_password,author.author_email,author.author_bio,author.register_timeFROM blog,author  WHERE blog.author_id=author.author_idAND blog_title LIKE "%"#{blogTitle}"%"</select><!-- 添加Blog --><insert id="addBlog" parameterType="Blog" useGeneratedKeys="true" keyProperty="blogId">INSERT INTO blog(blog_title,author_id)VALUES(#{blogTitle},#{author.authorId})</insert><!--修改 --><update id="updateBlog" parameterType="Blog">UPDATE blog SET blog_title=#{blogTitle},author_id=#{author.authorId}WHERE blog_id=#{blogId}</update><!--删除 --><delete id="deleteBlog" parameterType="int">delete from blog where blog_id=#{blogId}</delete></mapper>

 

 

5.4、测试

测试类不变