第一个MyBatis程序

布满荆棘的人生 2023-06-16 03:54 6阅读 0赞

开始学习MyBatis 今天记录一下第一个MyBatis程序

![20191124111322865.png][]

第一步：配置Config.xml：数据库信息 和 加载映射文件：

<?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>
    	<environments default="development">
    		<environment id="development">
    			<transactionManager type="JDBC" />
    			<dataSource type="POOLED">
    			
    				<property name="driver" value="oracle.jdbc.OracleDriver" />
    				<property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
    				<property name="username" value="sys as sysdba" />
    				<property name="password" value="123456" />
    			</dataSource>
    		</environment>
    	</environments>
    	<mappers>
    	
    		<mapper resource="org/cjr/entity/PersonMapper.xml" />
    	</mappers>
    </configuration>

第二步：映射文件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="org.cjr.entity.PersonMapper">
    
    	<select id="queryPersonById" resultType="org.cjr.entity.Person" parameterType="int">
    		select * from Person where id = #{id}
    	</select>
    	
    </mapper>

第三步：测试类：

package org.cjr.entity;
    
    
    import java.io.IOException;
    import java.io.Reader;
    
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    
    public class testMyBatis {
       public static void main(String[] args) throws IOException {
           //加载配置文件
       Reader reader = Resources.getResourceAsReader("config.xml");
           //sqlSessionFactory 
       SqlSessionFactory sqlSessionFactory = new  SqlSessionFactoryBuilder().build(reader);
          //session- 相当于connection
       SqlSession session = sqlSessionFactory.openSession();
          //映射文件中的namespace + id
      Person person = session.selectOne("org.cjr.entity.PersonMapper.queryPersonById",1);
          System.err.println(person);
          session.close();
       }
    }

结果：

![20191124111649930.png][]![2019112411172973.png][]

[20191124111322865.png]: https://img-blog.csdnimg.cn/20191124111322865.png
[20191124111649930.png]: https://img-blog.csdnimg.cn/20191124111649930.png
[2019112411172973.png]: https://img-blog.csdnimg.cn/2019112411172973.png