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[Java教程]MyBatis入门(三)


一、建立表

1.1、建立表,并插入数据

 

/*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=10 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,'金庸','qwertyuiop','wuji@163.com','这家伙很赖,什么也没留下','2015-10-29 11:48:24'),(8,'知道了','456789','456789@qq.com','哈哈哈哈哈雅虎','2015-10-29 14:03:27'),(9,'不知道','1234567890','123456@qq.com','哈哈哈哈哈雅虎','2015-10-29 14:01:16');/*!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

 

2.2、创建POJO类

 

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configruation

 

<?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>

 

 

 

2.3、创建mapper接口

 

public interface AuthorMapper {    /**   *   * @Title: findById     * @Description: TODO(根据查找一个用户)     * @param id   * @return Author   */  public Author findAuthorById(int authorId);}

 

 

 

2.4、创建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.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></mapper>

 

 

 

三、传入多个ID,进行查找使用List

3.1、更改Mapper接口

 

/**   *   * @Title: findAuthors     * @Description: TODO(根据多个ID进行查找)     * @param idLists   * @return List<Author>   */  public List<Author> findAuthors(List<Integer> idLists);

 

3.2、更改Mapper.

 

<!--根据多个ID查找 --><select id="findAuthors" resultMap="authorResultMap">SELECT * FROM authorWHERE author_id in<foreach collection="list" item="item" index="index" open="(" close=")" separator=",">#{item}</foreach>    <!-- collection:传入参数的名称 index:索引: item:collection的别名 --></select>

 

3.3、测试

 

@Test  public void testFindAuthors() {    //获取会话    SqlSession sqlSession=sqlSessionFactory.openSession();    //Mapper接口    AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);    List<Integer> list=new ArrayList<Integer>();        list.add(1);    list.add(3);    list.add(4);    list.add(6);    list.add(7);    //调用方法    List<Author> authors=authorMapper.findAuthors(list);    System.out.println(authors);    //关闭会话    sqlSession.close();  }

 

 

四、使用Map做为参数

4.1、在Mapper接口中增加相应方法

 

/**   *   * @Title: findAuthorsByMap     * @Description: TODO(使用Map做为参数)     * @param map   * @return List<Author>   */  public List<Author> findAuthorsByMap(Map<String, Object> map);

 

4.2、更改Mapper.

 

<!--使用Map查找 --><select id="findAuthorsByMap" resultMap="authorResultMap">SELECT * FROM author<!-- 参数使用Map的Key-->WHERE author_username LIKE "%"#{username}"%"or author_bio like"%"#{bio}"%"</select>

 

4.3、测试

 

@Test  public void testFindAuthorsByMap() {    //获取会话        SqlSession sqlSession=sqlSessionFactory.openSession();        //Mapper接口        AuthorMapper authorMapper=sqlSession.getMapper(AuthorMapper.class);        Map<String, Object> map=new HashMap<String, Object>();        map.put("username", "张");        map.put("bio", "哈");                //调用方法        List<Author> authors=authorMapper.findAuthorsByMap(map);        System.out.println(authors);        //关闭会话        sqlSession.close();        for(Author a:authors){          System.out.println(a.toString());        }  }

 

 

 

五、直接使用多个参数

5.1、Mapper接口

 

/**   *   * @Title: findAuthorsByParams     * @Description: TODO(使用多个参数     * @param id   * @param username   * @return List<Author>   */  public List<Author> findAuthorsByParams(int authorId,String authorUserName);

 

5.2、Mapper.

 

<!--直接使用多个参数 --><select id="findAuthorsByParams" resultMap="authorResultMap">SELECT * FROM authorWHERE author_id=#{0}OR author_username LIKE "%"#{1}"%"<!-- 其中,#{0}代表接收的是dao层中的第一个参数,#{1}代表dao层中第二参数,更多参数一致往后加即可。 --></select>

 

5.3、测试

 

@Test  public void testFindAuthorsByParams() {    //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.findAuthorsByParams(6,"张");        System.out.println(authors);        //关闭会话        sqlSession.close();        for(Author a:authors){          System.out.println(a.toString());        }  }

 

 

六、直接使用多个参数注解写法

6.1、Mapper接口

 

public List<Author> findAuthorsByParams(@Param("id") int authorId,@Param("username")String authorUserName);

 

 

 

6.2、Mapper.

<!--使用注解的方式使用多个参数 --><select id="findAuthorsByParams" resultMap="authorResultMap">SELECT * FROM authorWHERE author_id=#{id}or author_username LIKE "%"#{username}"%"<!-- 使用注解的方式。,直接使用Param中的参数即可 --></select>