Mybatis增删改查总结（注解与配置文件两种方式）

待我称王封你为后i 2024-04-17 22:57 70阅读 0赞

前提：Mybatis环境搭建完成

直接上代码吧（我这里是配置文件方式来实现的）：

### 一、配置文件方式： ###

数据库表格：

![20190902170357600.png][]

StudentDao.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.chenlei.dao.StudentDao">
        
        <select id="findAll" resultType="com.chenlei.domain.Student">
            select * from student;
        </select>
    
        
        <insert id="saveStudent" parameterType="com.chenlei.domain.Student">
            insert into student(name,sex,birthday) values(#{name},#{sex},#{birthday});
        </insert>
    
        
        <update id="updateStudent" parameterType="com.chenlei.domain.Student">
            update student set name = #{name},sex = #{sex},birthday=#{birthday} where id=#{id};
        </update>
    
        
        <delete id="deleteStudent" parameterType="Integer">
            delete from student where id = #{sid};
        </delete>
    
        
        <select id="findById" parameterType="int" resultType="com.chenlei.domain.Student">
            select * from student where id = #{sid};
        </select>
    
        
        <select id="findByName" parameterType="string" resultType="com.chenlei.domain.Student">
            select * from student where name like #{name};
        </select>
    
        
        <select id="findTotal" resultType="int">
            select count(*) from student;
        </select>
    </mapper>

测试类:

public class MybatisTest {
        private InputStream in;
        private SqlSession sqlSession;
        private StudentDao studentDao;
    
        //用于测试方法测试之前执行
        @Before
        public void init() throws IOException {
            //1.读取配置文件
            in = Resources.getResourceAsStream("SqlMapConfig.xml");
            //2.创建SqlSessionFactory工厂
            SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
            //3.使用工厂生产SqlSession对象
            sqlSession = factory.openSession();
            ///4.使用SqlSession创建Dao接口的代理对象
            studentDao = sqlSession.getMapper(StudentDao.class);
        }
    
        //用于测试方法之后执行
        @After
        public void destroy() throws IOException {
            //提交事务
            sqlSession.commit();
            //6.释放资源
            sqlSession.close();
            in.close();
        }
        
        @Test
        public void findAll() {
            //执行查询所有对象方法
            List<Student> students = studentDao.findAll();
            for (Student student : students) {
                System.out.println(student);
            }
        }
    
        @Test
        public void testSave(){
            Student student = new Student();
            student.setName("mybatis");
            student.setSex("女");
            student.setBirthday(new Date());
    
            //5.执行保存方法
            studentDao.saveStudent(student);
        }
    
        @Test
        public void testUpdate(){
            Student student = new Student();
            student.setName("coco");
            student.setId(25);
            student.setSex("女");
            student.setBirthday(new Date());
    
            //执行保存方法
            studentDao.updateStudent(student);
        }
    
        @Test
        public void testDelete(){
            //执行删除方法
            studentDao.deleteStudent(22);
        }
    
        @Test
        public void testSelectOne(){
            //执行查询一个方法
            Student student = studentDao.findById(25);
            System.out.println(student);
        }
    
        @Test
        public void testfindByName(){
            //执行根据名字模糊查询方法
            List<Student> students = studentDao.findByName("%王%");
            for (Student student : students) {
                System.out.println(student);
            }
        }
    
        @Test
        public void testfindTotal(){
            //执行函数统计查询方法
            int total = studentDao.findTotal();
            System.out.println(total);
        }
    }

StudentDao:

* 持久层接口
     */
    public interface StudentDao {
        /**
         * 查找所有操作
         * @return
         */
        List<Student> findAll();
    
        /**
         * 保存学生
         */
        void saveStudent(Student student);
    
        /**
         * 更新操作
         * @param student
         */
        void updateStudent(Student student);
    
        /**
         * 根据id删除学生
         * @param id
         */
        void deleteStudent(Integer id);
    
        /**
         * 根据id查询学生
         * @param id
         */
        Student findById (Integer id);
    
        /**
         * 根据名称进行模糊查询
         * @return
         * @param s
         */
        List<Student> findByName(String s);
    
        /**
         * 查询总学生数
         * @return
         */
        int findTotal();
    }

### 二、注解方式： ###

注意：注解方式与配置文件方式除了需要修改的部分有代码展示，其他与上面配置一致；且配置文件代码与注解方式代码不能同             时存在，所以需要把studentDao.xml删除。

StudentDao修改：

* 持久层接口
     */
    public interface StudentDao {
        /**
         * 查找所有操作
         * @return
         */
        @Select("select * from student")
        List<Student> findAll();
    
        /**
         * 保存学生
         */
        @Insert("insert into student(name,sex,birthday) values(#{name},#{sex},#{birthday})")
        void saveStudent(Student student);
    
        /**
         * 更新操作
         * @param student
         */
        @Update("update student set name = #{name},sex = #{sex},birthday=#{birthday} where id=#{id}")
        void updateStudent(Student student);
    
        /**
         * 根据id删除学生
         * @param id
         */
        @Delete("delete from student where id = #{sid}")
        void deleteStudent(Integer id);
    
        /**
         * 根据id查询学生
         * @param id
         */
        @Select("select * from student where id = #{sid};")
        Student findById (Integer id);
    
        /**
         * 根据名称进行模糊查询
         * @return
         * @param s
         */
        @Select("select * from student where name like #{name}")
        List<Student> findByName(String s);
    
        /**
         * 查询总学生数
         * @return
         */
        @Select("select count(*) from student")
        int findTotal();
    }

SqlMapConfig.xml(改为注解模式):

<mappers>
            <mapper class="com.chenlei.dao.StudentDao"/>
        </mappers>

对于细节配置不清楚的可以查看我的入门总结：

[https://blog.csdn.net/chlei\_/article/details/100187907][https_blog.csdn.net_chlei_article_details_100187907]

[20190902170357600.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/17/4c88914648db4832886c509453fee7a9.png
[https_blog.csdn.net_chlei_article_details_100187907]: https://blog.csdn.net/chlei_/article/details/100187907