spring boot + mybaits 操作数据库

2024-11-28 技术教程

spring boot 访问 mysql
方式三：spring boot + mybaits

pom 文件引入依赖

<dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.0.1</version></dependency><dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId></dependency>

配置mybaits

mybatis

# 对应实体类的包名mybatis.typeAliasesPackage=com.example.demo.model# mapper.xml文件所在位置mybatis.mapperLocations=classpath:**/mapper/*.xml

加入 entity mapper service controller 文件
entity

public class User { @Id @GeneratedValue(strategy= GenerationType.IDENTITY) private Long id; private String name; private int age; private String sex; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; }}

mapper

@Mapperpublic interface UserMapper { User findUserById(Long id); int add(User user); int update(User user);}

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.example.demo.dao.mybatis.UserMapper"> <resultMap id = "BaseResult" type = "com.example.demo.model.User"> <result property = "id" column = "id"/> <result property = "name" column = "name"/> </resultMap> <select id = "findUserById" resultMap = "BaseResult"> SELECT * FROM user where id = #{id} </select> <insert id="add" useGeneratedKeys="true" keyProperty="id" keyColumn="id"> insert into user (name,age,sex) values (#{name},#{age},#{sex}) </insert> <update id = "update" parameterType="com.example.demo.model.User"> update user set name = #{name} ,age = #{age} ,sex = #{sex} where id = ${id} </update></mapper>

service

@Servicepublic class MybatisUserService { @Autowired UserMapper userDao; public int add(User user){ return userDao.add(user); } public int update(User user){ return userDao.update(user); } public User getById(long id){ return userDao.findUserById(id); }}

controller

@RestController@RequestMapping("/mybatisUser")public class MybatisUserController { @Autowired MybatisUserService userService; @RequestMapping(value = "/add",method = RequestMethod.POST) public Object addUser(@RequestBody User user){ return userService.add(user); } @RequestMapping(value = "/update",method = RequestMethod.PUT) public Object updateUser(@RequestBody User user){ return userService.update(user); } @RequestMapping(value = "/find",method = RequestMethod.GET) public Object updateUser(long id){ return userService.getById(id); }}

主类上加扫描 mapper 路径

@SpringBootApplication@MapperScan("com.example.demo.dao.mybatis")public class DemoApplication { public static void main(String[] args) { SpringApplication.run(DemoApplication.class, args); }}

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