如何使用Go语言编写上门做菜系统中的用户注册模块？

CREATE TABLE `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户ID',
  `username` varchar(20) NOT NULL COMMENT '用户名',
  `password` varchar(32) NOT NULL COMMENT '密码',
  `phone` varchar(20) NOT NULL COMMENT '手机号码',
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `username` (`username`),
  UNIQUE KEY `phone` (`phone`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户表';

require (
    github.com/gin-gonic/gin v1.6.3
    github.com/aliyun/alibaba-cloud-sdk-go/sdk v1.0.0
)

package main

import (
    "net/http"

    "github.com/gin-gonic/gin"
)

func main() {
    router := gin.Default()

    // 绑定注册函数
    router.POST("/register", registerHandler)

    router.Run()
}

func registerHandler(c *gin.Context) {
    // TODO
}

func registerHandler(c *gin.Context) {
    // 获取请求参数
    username := c.PostForm("username")
    password := c.PostForm("password")
    phone := c.PostForm("phone")

    // 参数校验
    if username == "" || password == "" || phone == "" {
        c.JSON(http.StatusBadRequest, gin.H{
            "code":    http.StatusBadRequest,
            "message": "请求参数错误",
        })
        return
    }

    // TODO: 更多参数校验操作
}

func registerHandler(c *gin.Context) {
    // 获取请求参数
    username := c.PostForm("username")
    password := c.PostForm("password")
    phone := c.PostForm("phone")

    // 参数校验
    if username == "" || password == "" || phone == "" {
        c.JSON(http.StatusBadRequest, gin.H{
            "code":    http.StatusBadRequest,
            "message": "请求参数错误",
        })
        return
    }

    // 检查用户是否已存在
    var user User
    if err := db.Where("username = ?", username).Or("phone = ?", phone).First(&user).Error; err == nil {
        c.JSON(http.StatusBadRequest, gin.H{
            "code":    http.StatusBadRequest,
            "message": "用户名或手机号已被注册",
        })
        return
    }

    // TODO: 插入用户数据并发送短信通知
}

import "github.com/aliyun/alibaba-cloud-sdk-go/services/dysmsapi"

// 插入用户数据并发送短信通知
user := User{
    Username: username,
    Password: utils.MD5(password),
    Phone:    phone,
}
if err := db.Create(&user).Error; err != nil {
    c.JSON(http.StatusInternalServerError, gin.H{
        "code":    http.StatusInternalServerError,
        "message": "系统错误",
    })
    return
}

// 调用阿里云短信API发送短信通知
client, _ := dysmsapi.NewClientWithAccessKey("cn-hangzhou", "AKID", "AKSECRET")
request := dysmsapi.CreateSendSmsRequest()
request.Scheme = "https"
request.PhoneNumbers = phone
request.SignName = "签名"
request.TemplateCode = "模板ID"
request.TemplateParam = `{"code": "123456"}`
response, err := client.SendSms(request)
if err != nil || !response.IsSuccess() {
    c.JSON(http.StatusInternalServerError, gin.H{
        "code":    http.StatusInternalServerError,
        "message": "短信发送失败",
    })
    return
}

c.JSON(http.StatusOK, gin.H{
    "code":    http.StatusOK,
    "message": "注册成功",
})