MyBatis入门（二）---一对一，一对多
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
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
