代码及配置整合

创建实体类，与数据库对应

创建 mapper、service 和 controller

    @Autowired
    UserService userService;

    @ResponseBody
    @GetMapping("/user")
    public com.vazquez.bootstudy.model.User getById(@RequestParam("id") Long id) {
   
        return userService.getById(id);
    }

创建 sql xml

<?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="com.vazquez.bootstudy.mapper.UserMapper">
    <select id="getUser" resultType="com.vazquez.bootstudy.model.User">
        select * from user where id = #{id}
    </select>
</mapper>

修改 mybatis 配置

设置开始驼峰命名，不然数据会显示不出来，以下两种方式选择其一

1. 在 mybatis 的 xml 配置文件中修改

<?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>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
</configuration>

2. 在 application.yml 中修改

mybatis