Java

SpringBoot2 学习笔记03 MyBatis

本文含有: SpringBoot2中关于MyBatis使用教程, CURD查询增加修改删除, 注解开发, 自定义映射, association, collection, 模糊查询, 批量删除, 动态表名, 分页, resultMap使用方法

更新记录

20231207：第一版

20240309: 补充章节 “resultMap 重点补充”

20241122：重构系列

配置环境

导入数据

-- 创建学生表
CREATE TABLE student (
    id INT PRIMARY KEY AUTO_INCREMENT,  -- 学生ID，主键，自增
    name VARCHAR(50) NOT NULL,          -- 学生姓名
    age INT NOT NULL,                   -- 学生年龄
    teacher_id INT                      -- 所属老师ID
);

-- 创建老师表
CREATE TABLE teacher (
    id INT PRIMARY KEY AUTO_INCREMENT,  -- 老师ID，主键，自增
    name VARCHAR(50) NOT NULL          -- 老师姓名
);

INSERT INTO student (id, name, age, teacher_id) VALUES
(1, '小明', 16, 1),   -- 小明 对应 张老师
(2, '小红', 17, 1),   -- 小红 对应 张老师
(3, '小华', 15, 2),   -- 小华 对应 李老师
(4, '小丽', 16, 2),   -- 小丽 对应 李老师
(5, '小强', 17, 3),   -- 小强 对应 王老师
(6, '小芳', 16, 3),   -- 小芳 对应 王老师
(7, '小亮', 15, 4),   -- 小亮 对应 赵老师
(8, '小霞', 17, 4);   -- 小霞 对应 赵老师

INSERT INTO teacher (id, name) VALUES
(1, '张老师'),
(2, '李老师'),
(3, '王老师'),
(4, '赵老师');

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <!-- 组名 -->
    <groupId>org.example</groupId>
    <!-- 项目ID -->
    <artifactId>demo</artifactId>
    <!-- 项目版本 -->
    <version>1.0-SNAPSHOT</version>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.7.18</spring-boot.version>
        <alibaba.druid.version>1.2.21</alibaba.druid.version>
        <mybatis.plus.boot.version>3.5.3.2</mybatis.plus.boot.version>
        <mysql.boot.version>8.0.33</mysql.boot.version>
        <lombok.version>1.18.30</lombok.version>
    </properties>

    <!-- 管理依赖版本 -->
    <dependencyManagement>
        <dependencies>
            <!-- SpringBoot的依赖配置-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!-- 阿里数据库连接池 -->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid-spring-boot-starter</artifactId>
                <version>${alibaba.druid.version}</version>
            </dependency>

            <!-- MP -->
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>${mybatis.plus.boot.version}</version>
            </dependency>

            <!-- MYSQL -->
            <dependency>
                <groupId>com.mysql</groupId>
                <artifactId>mysql-connector-j</artifactId>
                <version>${mysql.boot.version}</version>
            </dependency>

            <!-- lombok -->
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <!-- 应用依赖 -->
    <dependencies>
        <!-- Web模块 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- 阿里数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
        </dependency>

        <!-- MP -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>

        <!-- MYSQL -->
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
        </dependency>


        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>public</id>
            <name>aliyun nexus</name>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>public</id>
            <name>aliyun nexus</name>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>
</project>

添加配置文件

# 应用服务 WEB 访问端口
server:
  port: 8080

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/spring_db?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
    Studentname: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
  mapper-locations: classpath:mapper/*.xml
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    cache-enabled: true

创建 entity 实体类

package org.example.entity;

import lombok.Data;

@Data
public class Student {
    private Integer id;
    private String name;
    private Integer age;
    private Integer teacherId;
}


package org.example.entity;

import lombok.Data;

@Data
public class Teacher {
    private Integer id;
    private String name;
}

创建 org.example/mapper/StudentMapper.java

package org.example.mapper;

import org.apache.ibatis.annotations.Mapper;
import org.example.entity.Student;

import java.util.List;

@Mapper
public interface StudentMapper {

    // 查询全部学生
    List<Student> selectStudent();

    // 根据id查询学生
    Student selectStudentById(int id);
}

创建 XML:resources/mapper/StudentMapper.xml，添加 Select 语句，通过 #{} 方式获取参数。

<?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="org.example.mapper.StudentMapper">
    <select id="selectStudent" resultType="org.example.entity.Student">
        select *
        from student
    </select>
    <select id="selectStudentById" resultType="org.example.entity.Student">
        select *
        from student
        where id = #{id}
    </select>
</mapper>

调用

@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        System.out.println(studentMapper.selectStudent());
        System.out.println(studentMapper.selectStudentById(2));
        return "show";
    }
}

输出

[Student(id=1, name=小明, age=16, teacherId=1), Student(id=2, name=小红, age=17, teacherId=1), Student(id=3, name=小华, age=15, teacherId=2), Student(id=4, name=小丽, age=16, teacherId=2), Student(id=5, name=小强, age=17, teacherId=3), Student(id=6, name=小芳, age=16, teacherId=3), Student(id=7, name=小亮, age=15, teacherId=4), Student(id=8, name=小霞, age=17, teacherId=4)]
Student(id=2, name=小红, age=17, teacherId=1)

CURD

查询

当参数比较多的情况下，key 通过 Map 的方式传递。

在 StudentMapper 中添加对应方法

@Mapper
public interface StudentMapper {

    // 查询全部学生
    List<Student> selectStudent();

    // 根据id查询学生
    Student selectStudentById(int id);

    // 通过 Map
    Student selectStudentByMap(Map<String, Object> map);
}

在 StudentMapper.xml 中添加 Select 语句

<?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="org.example.mapper.StudentMapper">
    <!-- 1. 查询所有 -->
    <select id="selectStudent" resultType="org.example.entity.Student">
        select *
        from student
    </select>

    <!-- 2. 查询ID -->
    <select id="selectStudentById" resultType="org.example.entity.Student">
        select *
        from student
        where id = #{id}
    </select>

    <!-- 3. 使用 Map 查询 -->
    <select id="selectStudentByMap" resultType="org.example.entity.Student">
        select *
        from student
        where id = #{id} and name = #{name}
    </select>
</mapper>

开始测试

@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        System.out.println(studentMapper.selectStudent());
        System.out.println(studentMapper.selectStudentById(2));
        Map<String, Object> map = new HashMap<>();
        map.put("id", 3);
        map.put("name", "小华");
        System.out.println(studentMapper.selectStudentByMap(map));
        return "show";
    }
}

增加

在 StudentMapper 中添加对应方法

int addStudent(Student Student);

你可能疑问，为什么下面的 teacherId 为什么不能写成 teacher_id? 因为他是对应实体类 Student，这一点我会在下一节自定义映射会说明。

<insert id="addStudent" parameterType="org.example.entity.Student">
    insert into student (name, age, teacher_id)
    values (#{name}, #{age}, #{teacherId})
</insert>

开始插入数据

@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        Student Student = new Student();
        Student.setName("测试");
        Student.setAge(22);
        Student.setTeacherId(3);
        System.out.println(studentMapper.addStudent(Student));
        return "show";
    }
}

修改

在 StudentMapper 中添加对应方法

int updateStudent(Student Student);

在 StudentMapper.xml 中添加 update 语句

<update id="updateStudent" parameterType="org.example.entity.Student">
    update student
    set name=#{name}
    where id = #{id}
</update>

开始插入数据

@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        Student Student = new Student();
        Student.setId(1);
        Student.setName("小明-update");
        System.out.println(studentMapper.updateStudent(Student));
        return "show";
    }
}

删除

在 StudentMapper 中添加对应方法

int deleteStudent(int id);

在 StudentMapper.xml 中添加 Select 语句

<update id="deleteStudent" parameterType="org.example.entity.Student">
    delete
    from student
    where id = #{id}
</update>

开始

@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        System.out.println(studentMapper.deleteStudent(9));
        return "show";
    }
}

自定义映射

好了，已经学会了最基础的增删改查，接下来我们来看下如何进行自定义字段查询和多表查询

resultMap

现在面临一个问题，我希望同时查询学生表和老师表，但是他们同时拥有 name 字段，我该怎么办？

这个时候我们就应该引出 resultMap 自定义映射了。

我们先新建一个 VO 对象，用来专门与数据库字段交互。

package org.example.vo;

import lombok.Data;

@Data
public class ShowVO {
    private Integer id;
    private String name;
    private Integer age;
    private Integer teacherId;
    private String teacherName;
}

去 Mapper 新建一个方法

@Mapper
public interface StudentMapper {
    List<ShowVO> selectStudentTeacher();
}

StudentMapper.xml

<resultMap id="StudentTeacherMap" type="org.example.vo.ShowVO">
    <!-- id为示自定义映射的唯一标识 -->
    <id column="id" property="id"/>
    <!-- column是数据库表的列名 , property是对应实体类的属性名 -->
    <result column="name" property="name"/>
    <result column="age" property="age"/>
    <result column="tid" property="teacherId"/>
    <result column="tname" property="teacherName"/>
</resultMap>

<select id="selectStudentTeacher" resultMap="StudentTeacherMap">
    select s.id, s.name, s.age, t.id as tid, t.name as tname
    from student s, teacher t
    where s.teacherId = t.id
</select>

执行，剩下就不多说了

@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        System.out.println(studentMapper.selectStudentTeacher());
        // [ShowVO(id=1, name=小明-update, age=16, teacherId=1, teacherName=张老师), ShowVO(id=2, name=小红, age=17, teacherId=1, teacherName=张老师), ShowVO(id=3, name=小华, age=15, teacherId=2, teacherName=李老师), ShowVO(id=4, name=小丽, age=16, teacherId=2, teacherName=李老师), ShowVO(id=5, name=小强, age=17, teacherId=3, teacherName=王老师), ShowVO(id=6, name=小芳, age=16, teacherId=3, teacherName=王老师), ShowVO(id=7, name=小亮, age=15, teacherId=4, teacherName=赵老师), ShowVO(id=8, name=小霞, age=17, teacherId=4, teacherName=赵老师), ShowVO(id=9, name=测试, age=22, teacherId=3, teacherName=王老师)]
        return "show";
    }
}

多对一映射 association

多对一也可以理解为一对一，特点是单个对象（如 Teacher），返回都是同级的。

创建实体

@Data
public class Student {
    private Integer id;
    private String name;
    private Integer age;
    private Integer teacherId;
    // 多个学生可以是同一个老师，即多对一
    private Teacher teacher;
}
  • 按查询结果嵌套查询
<resultMap id="StudentTeacherAssociationMap" type="org.example.vo.StudentTeacherVO">
    <id column="id" property="id"/>
    <result column="name" property="name"/>
    <result column="age" property="age"/>
    <result column="teacher_id" property="teacherId"/>
    <!-- column是数据库表的列名 , property是对应实体类的属性名 -->
    <association property="teacher" javaType="org.example.entity.Teacher">
        <result column="tid" property="id"/>
        <result column="tname" property="name"/>
    </association>
</resultMap>

<select id="selectStudentTeacherAssociation" resultMap="StudentTeacherAssociationMap">
    select s.id, s.name, s.age, s.teacher_id, t.id as tid, t.name as tname
    from student s, teacher t
    where s.teacher_id = t.id
</select>
  • 按查询嵌套处理
    • javaType：代表关联的对象

该查询好处是不需要填写其他属性，但只能传递一个参数。

<select id="selectStudentTeacherAssociation" resultMap="StudentTeacherAssociationMap">
    select *
    from student
</select>
<resultMap id="StudentTeacherAssociationMap" type="org.example.vo.StudentTeacherVO">
    <!--association关联属性 property属性名 select查询方法 column关联列名-->
    <association property="teacher" select="getTeacher" column="id" javaType="org.example.entity.Teacher"/>
</resultMap>
<!--
上面传递过来的id, association中column配置
-->
<select id="getTeacher" resultType="org.example.entity.Teacher">
    select *
    from teacher
    where id = #{tid}
</select>
  • 不管使用哪种方式结果都是一样的
@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        System.out.println(studentMapper.selectStudentTeacherAssociation());
        // [StudentTeacherVO(id=1, name=小明-update, age=16, teacherId=1, teacher=Teacher(id=1, name=张老师)), StudentTeacherVO(id=2, name=小红, age=17, teacherId=1, teacher=Teacher(id=1, name=张老师)), StudentTeacherVO(id=3, name=小华, age=15, teacherId=2, teacher=Teacher(id=2, name=李老师)), StudentTeacherVO(id=4, name=小丽, age=16, teacherId=2, teacher=Teacher(id=2, name=李老师)), StudentTeacherVO(id=5, name=小强, age=17, teacherId=3, teacher=Teacher(id=3, name=王老师)), StudentTeacherVO(id=6, name=小芳, age=16, teacherId=3, teacher=Teacher(id=3, name=王老师)), StudentTeacherVO(id=7, name=小亮, age=15, teacherId=4, teacher=Teacher(id=4, name=赵老师)), StudentTeacherVO(id=8, name=小霞, age=17, teacherId=4, teacher=Teacher(id=4, name=赵老师)), StudentTeacherVO(id=9, name=测试, age=22, teacherId=3, teacher=Teacher(id=3, name=王老师))]
        return "show";
    }
}

一对多映射 collection

一对多、多对多。目标数据结构是集合（如 List<Student>）。

@Data
public class TeacherStudentVO {
    private int id;
    private String name;
    //一个老师多个学生
    private List<Student> students;
}

List<TeacherStudentVO> selectStudentTeacherCollection();
  • 按查询结果嵌套查询
<resultMap id="TeacherStudentCollectionMap" type="org.example.vo.TeacherStudentVO">
    <id column="tid" property="id"/>
    <result column="tname" property="name"/>
    <!-- column是数据库表的列名 , property是对应实体类的属性名 -->
    <collection property="students" ofType="org.example.entity.Student">
        <result column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="age" property="age"/>
        <result column="teacher_id" property="teacherId"/>
    </collection>
</resultMap>

<select id="selectTeacherStudentCollection" resultMap="TeacherStudentCollectionMap">
    select s.id, s.name, s.age, s.teacher_id, t.id as tid, t.name as tname
    from student s, teacher t
    where s.teacher_id = t.id
</select>
  • 按查询嵌套处理
    • javaType：集合的类型，这一点和多对一是不同的
    • ofType：集合 中 元素的类型，即每个学生对应一个 Student 对象。
<select id="selectTeacherStudentCollection" resultMap="TeacherStudentCollectionMap">
    select *
    from teacher
</select>
<resultMap id="TeacherStudentCollectionMap" type="org.example.vo.TeacherStudentVO">
    <!--association关联属性 property属性名 select查询方法 column关联列名-->
    <collection property="students" javaType="ArrayList" ofType="org.example.entity.Student" column="id"
                select="getStudent"/>
</resultMap>
<!--
上面传递过来的id, association中column配置
-->
<select id="getStudent" resultType="org.example.entity.Teacher">
    select *
    from student
    where id = #{id}
</select>
  • 不管使用哪种方式结果都是一样的
@Data
@RestController
@Slf4j
public class HelloController {

    @Autowired
    private StudentMapper studentMapper;

    @GetMapping("/")
    public String show() {
        System.out.println(studentMapper.selectTeacherStudentCollection());
        // [TeacherStudentVO(id=1, name=张老师, students=[Student(id=1, name=小明-update, age=16, teacherId=1), Student(id=2, name=小红, age=17, teacherId=1)]), TeacherStudentVO(id=2, name=李老师, students=[Student(id=3, name=小华, age=15, teacherId=2), Student(id=4, name=小丽, age=16, teacherId=2)]), TeacherStudentVO(id=3, name=王老师, students=[Student(id=5, name=小强, age=17, teacherId=3), Student(id=6, name=小芳, age=16, teacherId=3), Student(id=9, name=测试, age=22, teacherId=3)]), TeacherStudentVO(id=4, name=赵老师, students=[Student(id=7, name=小亮, age=15, teacherId=4), Student(id=8, name=小霞, age=17, teacherId=4)])]
        return "show";
    }
}

特殊 SQL

模糊查询

<select id="testMohu" resultType="Student">
<!--select * from student where name like '%${mohu}%'-->
<!--select * from student where name like concat('%',#{mohu},'%')-->
select * from student where name like "%"#{mohu}"%"
</select>

批量删除

<delete id="deleteMore">
delete from student where id in (${ids})
</delete>

动态表名

<select id="getAllStudent" resultType="Student">
select * from ${tableName}
</select>

动态 SQL

直接拿上面的案例过来

  • if & where
<select id="selectStudentById" resultType="org.example.entity.Student">
    select *
    from student
    where id = #{id}
</select>

<select id="selectStudentById" resultType="org.example.entity.Student">
    select *
    from student
    <where>
        <if test="id != null">
            id = #{id}
        </if>
    </where>
</select>
  • set
<update id="updateStudent" parameterType="org.example.entity.Student">
    update student
    set name=#{name}
    where id = #{id}
</update>

<update id="updateStudent" parameterType="org.example.entity.Student">
    update student
    <set>
        <if test="name != null">
            name = #{name}
        </if>
    </set>
    <where>
        <if test="id != null">
            id = #{id}
        </if>
    </where>
</update>
  • choose
    • 适用于只想选择其中的一个。
<select id="selectStudentById" resultType="org.example.entity.Student">
    select *
    from student
    <where>
        <choose>
            <when test="id != null">
                and id = #{id}
            </when>
            <when test="name != null">
                and name = #{name}
            </when>
            <!-- 如果 id 和 name 都不存在 -->
            <otherwise>
            </otherwise>
        </choose>
    </where>
</select>
  • SQL 片段
<sql id="if-title-author">
    <if test="id != null">
        id = #{id}
    </if>
</sql>

<select id="selectStudentById" resultType="org.example.entity.Student">
    select *
    from student
    <where>
        <include refid="if-title-author"></include>
    </where>
</select>
  • Foreach

查询 1、3、5 的用户

List<Student> queryStudentForeach(Map map);

XML

<select id="queryStudentForeach" parameterType="map" resultType="org.example.entity.Student">
    select * from student
    <where>
        <!--
        collection:指定输入对象中的集合属性
        item:每次遍历生成的对象
        open:开始遍历时的拼接字符串
        close:结束时拼接的字符串
        separator:遍历对象之间需要拼接的字符串
        select * from student where 1=1 and (id=1 or id=3 or id=5)
      -->
        <foreach collection="ids" item="id" open="and (" close=")" separator="or">
            id=#{id}
        </foreach>
    </where>
</select>

调用

Map map = new HashMap();
List<Integer> ids = new ArrayList<Integer>();
ids.add(1);
ids.add(2);
ids.add(3);
map.put("ids", ids);

List<Student> Students = StudentMapper.queryStudentForeach(map);

System.out.println(Students);

分页

https://pagehelper.github.io/

  • 只有紧跟在PageHelper.startPage方法后的第一个Mybatis 的**查询（Select）**方法会被分页。
  • 对于带有for update的 sql，会抛出运行时异常
  • 嵌套结果方式会导致结果集被折叠

添加依赖

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.4.7</version>
</dependency>

配置 yml

pagehelper:
  helper-dialect: mysql
  reasonable: true
  support-methods-arguments: true
  params: count=countSql

调用

// 页码为1, 每页2条记录
PageHelper.startPage(1, 2);

// 跳过第一条记录, 返回2条记录
PageHelper.offsetPage(1, 2);

// 查询结果, 现在查询到2条
List<Student> StudentList = StudentMapper.selectByPage();
// 封装分页结果
PageInfo<Student> pageInfo = new PageInfo<>(StudentList);

注解开发

  • @select ()
  • @update ()
  • @Insert ()
  • @delete ()
@Mapper
public interface StudentMapper {
    @Select("select * from student where id = #{id}")
    Student selectStudentById(int id);

    @Insert("insert into student (name, age) values (#{name}, #{age})")
    int addStudent(Student Student);

    @Update("update student set name=#{name} where id = #{id}")
    int updateStudent(Student Student);

    @Delete("delete from student where id = #{id}")
    int deleteStudent(int id);
}
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最后更新于 Nov 22, 2024 00:00 UTC
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