MyBatis单表操作

1. mapper.xml修改 完成CRUD的操作

<?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.tongjun.mybatis.mapper.DepartmentMapper">

    <insert id="insert" parameterType="com.tongjun.mybatis.entity.Department">
        insert into tbl_department (id, name, tel) values (#{id}, #{name}, #{tel})
    </insert>

    <update id="update" parameterType="com.tongjun.mybatis.entity.Department">
        update tbl_department set name = #{name}, tel = #{tel} where id = #{id}
    </update>

    <delete id="deleteById" parameterType="string">
        delete from tbl_department where id = #{id}
    </delete>

    <select id="findAll" resultType="com.tongjun.mybatis.entity.Department">
        select * from tbl_department
    </select>

    <select id="findById" parameterType="string" resultType="com.tongjun.mybatis.entity.Department">
        select * from tbl_department where id = #{id}
    </select>
    
</mapper>

2. 动态代理的DepartmentMapper接口

package com.tongjun.mybatis.mapper;

import com.tongjun.mybatis.entity.Department;

import java.util.List;

/**
 * @author tj
 * @date 2022/8/25 10:47
 * @Version 1.0
 */
public interface DepartmentMapper {


    List<Department> findAll();

    int insert(Department department);

    int update(Department department);

    int deleteById(String id);

    Department findById(String id);

}

3. 实体类没有区别

package com.tongjun.mybatis.entity;

import lombok.Data;

import java.io.Serializable;

/**
 * @author tj
 * @date 2022/8/25 10:26
 * @Version 1.0
 */
@Data
public class Department implements Serializable {

    private String id;

    private String deptName;

    private String phone;

}

4. 编写测试程序

package com.tongjun.mybatis.app;

import com.tongjun.mybatis.entity.Department;
import com.tongjun.mybatis.mapper.DepartmentMapper;
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 java.io.InputStream;
import java.util.List;

/**
 * @author tj
 * @date 2022/8/25 10:28
 * @Version 1.0
 */
public class ApplicationTest {
    public static void main(String[] args) throws Exception{
        //拿到mybatis配置文件的流
        InputStream resourceAsStream = Resources.getResourceAsStream("mybatis-config.xml");
        //创建sqlSession工厂
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        //通过工厂拿到sqlSession对象
        SqlSession sqlSession = sqlSessionFactory.openSession();

        //获取Mapper接口的代理对象
        DepartmentMapper departmentMapper = sqlSession.getMapper(DepartmentMapper.class);

        List<Department> departmentList = departmentMapper.findAll();
        System.out.println("---------------departmentMapper.findAll()-----------------");
        departmentList.forEach(System.out::println);

        Department department = departmentMapper.findById("53e3803ebbf4f97968e0253e5ad4cc83");
        System.out.println("---------------departmentMapper.findById-----------------");
        System.out.println(department);
    }
}

5. 查看控制台输出信息

---------------departmentMapper.findAll()-----------------
Department(id=18ec781fbefd727923b0d35740b177ab, deptName=开发部, phone=110)
Department(id=53e3803ebbf4f97968e0253e5ad4cc83, deptName=测试产品部, phone=111)
Department(id=ee0e342201004c1721e69a99ac0dc0df, deptName=运维部, phone=112)
2022-08-25 10:52:55,350 2431   [           main] DEBUG pper.DepartmentMapper.findById  - ==>  Preparing: select * from tbl_department where id = ? 
2022-08-25 10:52:55,350 2431   [           main] DEBUG pper.DepartmentMapper.findById  - ==> Parameters: 53e3803ebbf4f97968e0253e5ad4cc83(String) 
2022-08-25 10:52:55,366 2447   [           main] DEBUG pper.DepartmentMapper.findById  - <==      Total: 1 
---------------departmentMapper.findById-----------------
Department(id=53e3803ebbf4f97968e0253e5ad4cc83, deptName=测试产品部, phone=111)