SpringBoot-Mybatis

10. SpringBoot-Mybatis

10.1 导入 MyBatis 所需要的依赖

<!-- mybatis-spring-boot-starter ： 整合 -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.0</version>
</dependency>

10.2 配置数据库信息

spring.datasource.username=root
spring.datasource.password=aadzj
spring.datasource.url=jdbc:mysql://localhost:3306/userdb?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

# mybatis整合 全限定类别名，关联配置文件
mybatis.type-aliases-package=com.dzj.pojo
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

10.3 测试数据库连接

10.4 创建实体类

导入lombok 依赖

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

创建实体类Student

文件路径：java--com--dzj--pojo--Student.java

package com.dzj.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Student {
    private String sno;
    private String sname;
    private String sclass;
    private String cname;
}

10.5 创建 Mapper 接口

文件路径：java--com--dzj--mapper--StudentMapper.java

package com.dzj.mapper;

import com.dzj.pojo.Student;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

// 这个注解表示了这是一个Mybatis的mapper类
@Mapper
@Repository
public interface StudentMapper {

    List<Student> queryStudentList();

    Student queryByStudentId(int sno);

    int addStudent(Student student);

    int updateStudent(Student student);

    int deleteStudent(int sno);
}

10.6 对应的Mapper映射文件

文件路径：resource--mybatis--mapper--StudentMapper.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.dzj.mapper.StudentMapper">
    <select id="queryStudentList" resultType="Student">
        select * from student
    </select>
    <select id="queryByStudentId" resultType="Student">
    select * from student where sno=#{sno}
    </select>

    <insert id="addStudent" parameterType="Student">
    insert into student(sno,sname,class,cname) values(#{sno},#{sname},#{sclass},#{cname})
    </insert>

    <update id="updateStudent" parameterType="Student">
    update student set sname=#{sname},class=#{sclass},cname=#{cname} where sno = #{sno}
    </update>

    <delete id="deleteStudent" parameterType="int">
    delete from student where sno = #{sno}
    </delete>
</mapper>

10.7 maven配置资源过滤问题

<resources>
    <resource>
        <directory>src/main/java</directory>
        <includes>
            <include>**/*.xml</include>
        </includes>
        <filtering>true</filtering>
    </resource>
</resources>

10.8 编写 StudentController进行测试

package com.dzj.controller;

import com.dzj.mapper.StudentMapper;
import com.dzj.pojo.Student;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class StudentController {

    @Autowired
    private StudentMapper studentMapper;

    @RequestMapping("/listStudent")
    public List<Student> queryStudentList(){
        List<Student> students = studentMapper.queryStudentList();
        for (Student student : students) {
            System.out.println(student);
        }
        return students;
    }
    @GetMapping("/queryStudent/{sno}")
    public Student queryStudent(@PathVariable("sno")int sno){
        Student student = studentMapper.queryByStudentId(sno);
        return student;
    }

    @GetMapping("/addStudent")
    public String addStudent(){
        int i = studentMapper.addStudent(new Student("105", "dengzi", "5班", "English"));
        return "添加成功";
    }

    @GetMapping("/deleteStudent/{id}")
    public String deleteStudent(@PathVariable("id")int id){
        studentMapper.deleteStudent(id);
        return "删除成功";
    }

    @GetMapping("/updateStudent")
    public String updateStudent(){
        studentMapper.updateStudent(new Student("101","wenliu","2班","语文"));
        return "修改成功";
    }
}