mybatis

Posted 2020-10-08

这次接着上次写增删改查吧。

现将上节的方法改造一下，改造测试类。

package cn.my.test;

import java.io.IOException;
import java.io.InputStream;

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 cn.my.mybatis.entity.User;

public class TestUser {
    private SqlSessionFactory factory;
    @Before
    public void setUp() throws IOException{
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        factory = new SqlSessionFactoryBuilder().build(inputStream);
    }
    
    @Test  
    public void testFindById(){  
        SqlSession session = factory.openSession();
        User user = session.selectOne("cn.my.mybatis.entity.User.findById", 1);  
        session.close();  
        System.out.println(user);  
    }  
}

 

简单的改造一下是为了后面写增删改查是每次都需要写setup方法中的代码。

下面我就不贴图了，我直接写代码了

1.新增

1.1首先添加新增的映射文件

<?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="cn.my.mybatis.entity.User">
    <select id="findById" parameterType="int" resultType="cn.my.mybatis.entity.User">
        select * from user where id=#{id}
    </select>
    <!-- 新增映射 -->
    <insert id="insertUser" parameterType="cn.my.mybatis.entity.User">
        INSERT INTO `user` (`username`,`birthday`,`sex`,`address`) 
        VALUES(‘id‘,‘username‘,‘birthday‘,‘sex‘,‘address‘)
    </insert>
</mapper>

 

 

1.2 .添加新增测试方法

package cn.my.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;

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 cn.my.mybatis.entity.User;

public class TestUser {
    private SqlSessionFactory factory;
    @Before
    public void setUp() throws IOException{
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        factory = new SqlSessionFactoryBuilder().build(inputStream);
    }
    
    @Test  
    public void testFindById(){  
        SqlSession session = factory.openSession();
        User user = session.selectOne("cn.my.mybatis.entity.User.findById", 1);  
        session.close();  
        System.out.println(user);  
    }  
    /**
     * 新增用户
     */
    @Test  
    public void testInserUser(){  
        SqlSession session = factory.openSession();
        User user = new User();
        user.setAddress("许昌");
        user.setUsername("曹操");
        user.setSex("男");
        user.setBirthday(new Date());
        session.insert("cn.my.mybatis.entity.User.insertUser", user); 
        session.commit();//这行记住一定不要忘，要不然提交不了
        session.close();  
        System.out.println(user);  
    }  
}

 

运行结果:

这样添加就写完了。如果需要添加完毕之后返回新增的id值。

user.xml代码

<!-- 新增映射 -->
<insert id="insertUser" parameterType="cn.my.mybatis.entity.User">
    <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
        SELECT LAST_INSERT_ID()
    </selectKey>
        INSERT INTO `user` (`username`,`birthday`,`sex`,`address`) 
        VALUES(#{username},#{birthday},#{sex},#{address})
</insert>

 

测试类代码

/**
     * 新增用户
     */
    @Test  
    public void testInserUser(){  
        SqlSession session = factory.openSession();
        User user = new User();
        user.setAddress("许昌");
        user.setUsername("曹操1");
        user.setSex("男");
        user.setBirthday(new Date());
        session.insert("cn.my.mybatis.entity.User.insertUser", user); 
        session.commit();
        session.close();  
        System.out.println(user.getId());  
    }  

 

看结果:

2.修改

1.1 user.xml添加代码

<!-- 修改用户 -->
    <update id="updateUser" parameterType="cn.my.mybatis.entity.User">
        UPDATE `user` 
        SET
          `username` = #{username},
          `birthday` = #{birthday},
          `sex` = #{sex},
          `address` = #{address} 
        WHERE `id` = #{id} ;
    </update>

 

2.1测试类代码

/**
     * 修改
     */
    @Test  
    public void testUpdateUser(){  
        SqlSession session = factory.openSession();
        User user = new User();
        user.setId(29);
        user.setAddress("许昌1");
        user.setUsername("曹操2");
        user.setSex("女");
        user.setBirthday(new Date());
        session.update("cn.my.mybatis.entity.User.updateUser", user); 
        session.commit();
        session.close();  
    }  

 

运行结果：

3.删除

user.xml

<delete id="deleteUser" parameterType="java.lang.Integer">
    delete from user where id=#{id}
</delete>

 

测试类代码

/**
     * 删除
     */
    @Test  
    public void testDeleteUser(){  
        SqlSession session = factory.openSession();
        session.delete("cn.my.mybatis.entity.User.deleteUser", 29); 
        session.commit();
        session.close();  
    } 

 

运行结构:删除id为29的。

 

好了以上就是一个最简单的例子。有时间我会继续往下写的，如果需要加群一起研究的可以q我，939705214，也可以添加群号581591235