MyBatis学习总结

1.引入jar包到lib目录下：只需要mybatis的一个mybatis.jar及数据库的jar包。

2。在src下新建xml配置文件，即上图中的conf.xml

 <?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>

     <!-- 定义别名 -->
     <typeAliases>
         <typeAlias type="com.hanqi.News" alias="News"/>

     </typeAliases>

     <!-- 环境配置 -->
         <environments default="test">
         <!-- 开发环境 -->
         <environment id="development">
             <!-- 事务管理器 -->
             <transactionManager type="JDBC" />
             <!-- 数据源 POOLED池连接;NOPOOLED 非池连接-->
             <dataSource type="POOLED">
                 <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                 <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
                 <property name="username" value="test" />
                 <property name="password" value="test" />
             </dataSource>
         </environment>
         <!-- 测试环境 -->
         <environment id="test">
             <transactionManager type="JDBC" />
             <dataSource type="POOLED">
                 <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                 <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
                 <property name="username" value="test" />
                 <property name="password" value="test" />
             </dataSource>
         </environment>
     </environments>

     <mappers>
         <mapper resource="com/hanqi/newsMapper.xml"/>

         <mapper class="com.hanqi.newsInterface"/>
     </mappers>
 </configuration>

3。新建数据库表NEWS，和实体类News.java

 package com.hanqi;

 import java.util.Date;

 public class News {

     private Integer id;
     private String title;
     private String contant;
     private Date createdate;
     private String author;
     public News(Integer id, String title, String contant, String author) {
         super();
         this.id = id;
         this.title = title;
         this.contant = contant;
         this.author = author;
     }

     public News(String title, String contant, String author) {
         super();
         this.title = title;
         this.contant = contant;
         this.author = author;
     }

     public News(Integer id, String title) {
         super();
         this.id = id;
         this.title = title;
     }

     public News() {
     }

     public Integer getId() {
         return id;
     }
     public void setId(Integer id) {
         this.id = id;
     }
     public String getTitle() {
         return title;
     }
     public void setTitle(String title) {
         this.title = title;
     }
     public String getContant() {
         return contant;
     }
     public void setContant(String contant) {
         this.contant = contant;
     }

     /**
      * @return the createdate
      */
     public Date getCreatedate() {
         return createdate;
     }
     /**
      * @param createdate the createdate to set
      */
     public void setCreatedate(Date createdate) {
         this.createdate = createdate;
     }
     /**
      * @return the author
      */
     public String getAuthor() {
         return author;
     }
     /**
      * @param author the author to set
      */
     public void setAuthor(String author) {
         this.author = author;
     }
     @Override
     public String toString() {
         return "News [id=" + id + ", title=" + title + ", contant=" + contant + ", createdate=" + createdate + "]";
     }
 }

4.新建映射配置文件：newsMapper.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.hanqi.newsMapper">
     <!--
         根据id查询得到一个News对象
      -->
      <select id="getNewsByID" parameterType="int" resultType="News">
          select * from news where id=#{id}
      </select>
      <!-- 定义结果集 -->
      <resultMap type="News" id="newsList">
          <!--  <id property="id" column="news_id"/>
          <result property="title" column="tit"/>
      -->
      </resultMap>

          <!-- 多数据查询 -->
      <select id="getAllList" resultMap="newsList">
          select * from news

      </select>

      <!-- 定义条件集 -->
      <parameterMap type="java.util.HashMap" id="titlelike">
          <parameter property="tit"/>
          <parameter property="aut"/>

      </parameterMap>

      <!-- 传多个条件多数据查询 -->
      <select id="getList" parameterMap="titlelike" resultMap="newsList">
          select * from news where title like '%'||#{tit}||'%' and author like '%'||#{aut}||'%'

      </select>
      <insert id="insertNews" parameterType="News">
          insert into news (id, title, contant, createdate, author) values ( HIBERNATE_SEQUENCE.nextval, #{title}, #{contant}, sysdate, #{author})

      </insert>
 </mapper>

5.新建测试用例，进行测试

 package com.hanqi;

 import static org.junit.Assert.*;

 import java.io.IOException;
 import java.io.Reader;
 import java.util.*;

 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.Test;

 public class TestMyBatis {

     @Test
     public void test() throws Exception {
         //1.加载配置文件到输入流里
         Reader reader = Resources.getResourceAsReader("conf.xml");

         //2.创建工厂类SqlSessionFactory
         SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(reader);

         //3.获取sqlSession
         SqlSession ss = ssf.openSession();

         //4.调用数据库操作
         //单数据查询
         News n = ss.selectOne("com.hanqi.newsMapper.getNewsByID",77);

         //输出结果
         System.out.println("n=" + n);

         //插入数据
         News n1 = new News("ddd","eeee","aaa");

         int i = ss.insert("com.hanqi.newsMapper.insertNews", n1);

         System.out.println("insert="+ i);

         //查询数据
         List<News> ln = ss.selectList("com.hanqi.newsMapper.getAllList");

         System.out.println("ln=......"+ln);

         //条件查询
         HashMap<String, Object> hm = new HashMap<String, Object>();

         hm.put("tit", "d");
         hm.put("aut", "a");

         List<News> ln1 = ss.selectList("com.hanqi.newsMapper.getList",hm);

         System.out.println("ln1=#######"+ln1);

         //测试注解update
         News n2 = new News(95,"测试MyBatis","测试","测试");

         int i1 = ss.update("com.hanqi.newsInterface.updateNews", n2);

         System.out.println("n3="+i1);

         //注解查询
         List<News> ln2 = ss.selectList("com.hanqi.newsInterface.selectList");

         System.out.println("ln2=@@@@@@@@"+ln2);

         //提交
         ss.commit();
         //关闭session
         ss.close();
         //关闭流
         reader.close();

     }

 }

6.也可以用注解代替映射配置文件，但是需要新建一个实体类对应的接口，在接口方法上加注解

 package com.hanqi;

 import java.util.List;

 import org.apache.ibatis.annotations.*;

 public interface newsInterface {

     @Update("update news set title=#{title}, contant=#{contant}, author=#{author} where id =#{id}")
     public int updateNews(News news);

     @Select("select * from news")
     public List<News> selectList();
 }