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MyBatis入门（二）---一对一，一对多

时间：2015-10-29 17:56:08      阅读：241      评论：0      收藏：0      [点我收藏+]

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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 XML 或注解，将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。‘,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

 技术分享

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

 

<?xml version="1.0" encoding="UTF-8"?>
<!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

 

<?xml version="1.0" encoding="UTF-8"?>
<!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 author
WHERE author_id=#{authorId}
</select>

<!-- 根据用户名，模糊查询 -->

<select id="findAuthorByName" parameterType="String" resultMap="authorResultMap">
SELECT * FROM author
WHERE 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 author
where 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.xml";
        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.xml

 

<?xml version="1.0" encoding="UTF-8"?>
<!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_time
FROM blog,author    
WHERE blog.author_id=author.author_id
AND 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_time
FROM blog,author    
WHERE blog.author_id=author.author_id
AND 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.xml";
        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.xml

 

<?xml version="1.0" encoding="UTF-8"?>
<!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_id
FROM blog,author,posts    
WHERE blog.author_id=author.author_id
AND blog.blog_id=posts.blog_id
AND 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_time
FROM blog,author    
WHERE blog.author_id=author.author_id
AND 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

技术分享

MyBatis入门（二）---一对一，一对多

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原文地址：http://www.cnblogs.com/liunanjava/p/4919752.html
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