实验二. Mybatis技术（2）

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原创 2023-06-23 18:24:08 192 阅读 AI 写同款· GEO 优化 ›

JavaEE实验二：MyBatis框架应用实验二： MyBatis框架应用现有一张员工表如下。利用本章所学知识完成员工管理系统。实现如下功能：根据id查询员工信息、新增员工信息、根据id修改员工信息、根据id删除员工信息。实验步骤1、创建maven项目，在pom.xml文件中配置依赖：MyBatis、mysql、Junit依赖2、新建实体类User3、在resources下建db.properties、mybatis-config.xml文件。注意要在mybatis-config.xml文件中引入db.properties文件4、在src 阅读详情

一、利用mapper.xml绑定接口实现对teacher表中的数据的增、删、改、查。

1、POJO实体类（Teacher.java）

package wzu.pojo;

public class Teacher {
    private int TNO;
    private String TNAME;
    private String TITLES;
    private String PHONE;

    @Override
    public String toString() {
        return "Teacher{" +
                "TNO=" + TNO +
                ", TNAME='" + TNAME + '\'' +
                ", TITLES='" + TITLES + '\'' +
                ", PHONE='" + PHONE + '\'' +
                '}';
    }

//省略set、get方法
}

2、mapper类【实体的映射类】（TeacherMapper.java）

是接口。

package wzu.mapper;

import wzu.pojo.Teacher;
import java.util.List;

public interface TeacherMapper {
    Teacher select_id();
    List<Teacher> select_all();
    List<Teacher> select_zhou();

    void add(Teacher teacher);
    void update();
    void delete();
}

3、mapper配置文件【mapper类的配置文件】（TeacherMapper.xml）

SQL映射文件，对应于相应的POJO，一般以 “ POJO的名+Mapper ” 来命名。

wzu.mapper.Teacher + Mapper = wzu.mapper.TeacherMapper

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--        ？？？？？？？？？-->
<mapper namespace="wzu.mapper.TeacherMapper">

    <select id="select_id" resultType="wzu.pojo.Teacher">
        select * from teacher where TNO='121002'
    </select>

    <select id="select_all" resultType="wzu.pojo.Teacher">
        select * from teacher;
    </select>

    <select id="select_zhou" resultType="wzu.pojo.Teacher">
        select * from teacher where TNAME like '周%'
    </select>

    <insert id="add" parameterType="wzu.pojo.Teacher">
<!--        INSERT INTO teacher(TNO,TNAME,TITLES,PHONE) VALUES ('210002', '王强', '高级实验师', '18041314946');-->
        INSERT INTO teacher(TNO,TNAME,TITLES,PHONE) VALUES (#{TNO},#{TNAME},#{TITLES},#{PHONE});
<!-- ps: values内容变量 与 该Teacher类中变量 一致！！       -->
    </insert>

    <update id="update" parameterType="wzu.pojo.Teacher">
        UPDATE `mybatis`.`teacher` SET `TNAME` = '李刚' WHERE (`TNO` = '121004');
    </update>

    <delete id="delete" parameterType="wzu.pojo.Teacher">
        DELETE FROM `mybatis`.`teacher` WHERE (`TNO` = '121001');
    </delete>
</mapper>

4、核心配置文件mybatis-config.xml

Mapper.xml配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--    引入database.properties文件-->
<!--    <properties resource="database.properties"/>-->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC"/>
<!--                useUnicode=true&characterEncoding=utf8&useSSL=false&-->
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
<!--    将mapper文件加入配置文件中-->
    <mappers>
        <mapper resource="wzu/mapper/TeacherMapper.xml"/>
    </mappers>
</configuration>

5、测试类

package wzu.test;

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 wzu.mapper.TeacherMapper;
import wzu.pojo.Teacher;


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

public class TeacherMapperTest {
    public static void main(String args[]) throws IOException{
        System.out.println("-------");
        String resource= "mybatis-config.xml";
        InputStream is=Resources.getResourceAsStream(resource);
        SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession=factory.openSession();

        TeacherMapper mapper = sqlSession.getMapper(TeacherMapper.class);

//（1）查询tno=“121002”的客户的记录；
        Teacher sel_id=mapper.select_id();
        System.out.println(sel_id.toString());
        System.out.println("");
//（2）查询全部教师记录；
        List<Teacher> sel_all=mapper.select_all();
        for (int i = 0; i < sel_all.size(); i++) {
            System.out.println(sel_all.get(i).toString());
        }
        System.out.println("");
//（3）查询姓周的教师记录；
        List<Teacher> sel_zhou=mapper.select_zhou();
        for (int i = 0; i < sel_zhou.size(); i++) {
            System.out.println(sel_zhou.get(i).toString());
        }
        System.out.println("");

//        sqlSession.getMapper(TeacherMapper.class).类名();
//                              ——该类，在 wzu\mapper\TeacherMapper.java
//（1）新增教师记录：（“210002”，“王强”，“高级实验师”，“18041314946”）；
        Teacher teacher=new Teacher();
        teacher.setTNO(210002);
        teacher.setTNAME("王强");
        teacher.setTITLES("高级实验师");
        teacher.setPHONE("18041314946");
        sqlSession.getMapper(TeacherMapper.class).add(teacher);
        sqlSession.commit();
//      操作，需要提交！
//（2）修改教师记录：将工号为“121004”的教师教师姓名改为“李刚”；
        sqlSession.getMapper(TeacherMapper.class).update();
        sqlSession.commit();
//（3）删除工号为“121001”的教师记录；
        sqlSession.getMapper(TeacherMapper.class).delete();
        sqlSession.commit();

        sqlSession.close();

    }

}

第1次运行;

第2次运行;

新增教师记录：（“210002”，“王强”，“高级实验师”，“18041314946”）；已完成。
修改教师记录：将工号为“121004”的教师教师姓名改为“李刚”。已完成。
删除工号为“121001”的教师记录,已完成。

二、利用注解方式绑定接口实现对teacher表中的数据的增、删、改、查。

1、POJO实体类（Teacher.java）——与上题相同

2、mapper类【实体的映射类：接口】（TeacherMapper.java）——相当于上题2、3

mapper类【实体的映射类】（TeacherMapper.java）
mapper配置文件【mapper类的配置文件】（TeacherMapper.xml）

package wzu.mapper;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import wzu.pojo.Teacher;

import java.util.List;

public interface TeacherMapper {
    @Select("select * from teacher where TNO=124001")
    Teacher select_id();

    @Select("select * from teacher;")
    List<Teacher> select_all();

    @Select("select * from teacher where TITLES='讲师'")
    List<Teacher> select_L();

    @Insert("INSERT INTO teacher(TNO,TNAME,TITLES,PHONE) VALUES (#{TNO},#{TNAME},#{TITLES},#{PHONE})")
    void add(Teacher teacher);

    @Update("UPDATE `mybatis`.`teacher` SET `TITLES` = '副教授' WHERE (`TNO` = '121002');")
    void update();

    @Delete("DELETE FROM `mybatis`.`teacher` WHERE (`TNO` = '124001');")
    void delete();

}

3、核心配置文件mybatis-config.xml

<mappers>
    <mapper class="wzu.mapper.TeacherMapper"/>
</mappers>

没有Mapper.xml配置文件，直接把Mapper类搞过去

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--    引入database.properties文件-->
<!--    <properties resource="database.properties"/>-->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC"/>
<!--                useUnicode=true&characterEncoding=utf8&useSSL=false&-->
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
<!--    将mapper文件加入配置文件中-->
    <mappers>
        <mapper class="wzu.mapper.TeacherMapper"/>
    </mappers>
</configuration>

4、测试类

//      调用getMapper(TeacherMapper.class)执行Mapper接口方法    
        TeacherMapper mapper = sqlSession.getMapper(TeacherMapper.class);

package wzu.test;

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 wzu.mapper.TeacherMapper;
import wzu.pojo.Teacher;

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

public class TeacherMapperTest {
    public static void main(String args[]) throws IOException{

        String resource= "mybatis-config.xml";
        InputStream is= Resources.getResourceAsStream(resource);
        SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession=factory.openSession();
//      调用getMapper(TeacherMapper.class)执行Mapper接口方法    ！！！！！！！！！！！！！！
        TeacherMapper mapper = sqlSession.getMapper(TeacherMapper.class);
//（1）查询tno=“124001”的客户的记录；
        Teacher sel_id=mapper.select_id();
        System.out.println(sel_id.toString());
        System.out.println("");
//（2）查询全部教师记录；
        List<Teacher> sel_all=mapper.select_all();
        for (Teacher t_all : sel_all) {
            System.out.println(t_all.toString());
        }
//        版权声明：本文为优快云博主「StudiousTiger」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
//        原文链接：https://blog.youkuaiyun.com/m0_45067620/article/details/118033802
        System.out.println("");
//（3）查询职称为讲师的教师记录；
        List<Teacher> sel_zhou=mapper.select_L();
        for (Teacher t_zhou : sel_zhou) {
            System.out.println(t_zhou.toString());
        }
        System.out.println("");
//（1）新增教师记录：（“210003”，“李志强”，“助教”，“18041304946”）；
        mapper.add(new Teacher(210003, "李志强", "助教", "18041304946"));
        sqlSession.commit();
//      操作，需要提交！
//（2）修改教师记录：将工号为“121002”的教师教师职称改为“副教授”；
        mapper.update();
        sqlSession.commit();
//（3）删除工号为“124001”的教师记录；
        mapper.delete();
        sqlSession.commit();

        sqlSession.close();
    }
}