MyBatis series (four) MyBatis CRUD

Foreword

By Bowen in front of a few already know how MyBatis query data in the database, now to introduce by (insert) delete (delete) change (update)

increase

Interface defines a method for increasing the binding file, the method returns the value of long, MyBatis is returned in the affected rows.

public interface MusicImp {
    public Long getinsertMusic(Music music);
}

SQL mapping file

<?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.mybatis.dao.MusicImp">
    
    <insert id="getinsertMusic" parameterType="com.mybatis.bean.Music">
        INSERT INTO test
        (id,name,music,musicurl)
        VALUES
        (#{id},#{name},#{music},#{musicurl});
    </insert>
    
</mapper>

Test category

public void test() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession addSession = sqlSessionFactory.openSession();
        try {
            MusicImp musicImp = addSession.getMapper(MusicImp.class);
            Music music = newMusic (9, "Shen Ning", "how many more years", null );
             Long addlong = musicImp.getinsertMusic (Music); 
            System.out.println (addlong); 
            addSession.commit (); 
        } a finally {
             / / the TODO: handle the finally clause 
            addSession.close (); 
        } 
    }

 

delete

Interface binding document defines a delete method, the return value Boolean methods, only two Boolean value is either true or false, use this return value can determine whether the deleted successfully.

public interface MusicImp {
    public boolean getdelectMusic(int id);
}

SQL mapping file

<?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.mybatis.dao.MusicImp">
    
    <delete id="getdelectMusic" parameterType="com.mybatis.bean.Music">
        delete from test
        where id = #{id};
    </delete>
    
</mapper>

Test category

    public void test() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession delectSession = sqlSessionFactory.openSession();
        try {
            MusicImp musicImp = delectSession.getMapper(MusicImp.class);
            boolean deleteboolean = musicImp.getdelectMusic(7);
            System.out.println(deleteboolean);
            delectSession.commit();
        } finally {
            // TODO: handle finally clause
            delectSession.close();
        }
    }

 

modify

Interface binding document defines a modification method, the return value Boolean methods, only two Boolean value is either true or false, use this return value can determine whether the deleted successfully.

public interface MusicImp {
    public boolean getupdateMusic(@Param("musicurl")String musicurl,@Param("id")String id);
}

SQL mapping file

<?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.mybatis.dao.MusicImp">
    
    <update id="getupdateMusic" parameterType="com.mybatis.bean.Music">
        update test set musicurl = #{musicurl}
        where id = #{id};
    </update>
    
</mapper>

Test category

    public void test() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession updateSession = sqlSessionFactory.openSession();
        try {
            MusicImp musicImp = updateSession.getMapper(MusicImp.class);
            boolean updatemusic = musicImp.getupdateMusic
                    ("http://music.163.com/song/media/outer/url?id=392897.mp3", "5");
            if (updatemusic) {
                System.out.println("更新成功");
            } else {
                System.out.println("更新失败");
            }
            
            updateSession.commit();
        } finally {
            updateSession.close();
        }
    }