Go Web 开发必备核心理论 | 极客日志

Go Web 开发必备核心理论 | 极客日志

import (
	_ "github.com/go-sql-driver/mysql"
	"github.com/jmoiron/sqlx"
)
// 核心的两步
DB, err := sqlx.Open("mysql", "root:1234@tcp(localhost:3306)/goweb?parseTime=true&loc=Local")
DB.Ping()

// 语句
queryCreate := "insert into user (id,name) values (?,?)"
queryDelete := "delete from user where id =?"
queryUpdate := "update user set name=? where id=?"
queryQuery := "select * from user"

// 执行
// 增：DB.Exec(query, 1, "白小纯")
// 删：DB.Exec(query, 1)
// 改：DB.Exec(query, "夜藏", 1)
// 查：rows, err := DB.Query(query)
// for rows.Next() { rows.Scan(&id, &name) }

func serv(w http.ResponseWriter, r *http.Request) {
	// cookie 赋值
	cookie := &http.Cookie{
		Name:    "session_id",
		Value:   "cookie",
		Expires: time.Now().Add(time.Second),
	}
	http.SetCookie(w, cookie)

	// 获取单个 cookie
	c, _ := r.Cookie("session_id")
	_, err := fmt.Fprintln(w, c.Name, c.Value, c.Expires)
	if err != nil {
		fmt.Println("...")
	}

	// 循环获取 cookie
	cs := r.Cookies()
	for n, co := range cs {
		_, err = fmt.Fprintln(w, n, co.Name)
	}
}

// 后端界面
func temp(w http.ResponseWriter, r *http.Request) {
	add := template.FuncMap{"add": Add}
	t := template.New("index").Funcs(add)
	t, _ = t.ParseFiles("new_add")
	t.Execute(w, nil)
}

<!-- 前端 -->
{{add 0 0}}

<form action="upload" enctype="multipart/form-data" method="post">
	上传照片：<input type="file" name="photo">
</form>

func upload(w http.ResponseWriter, r *http.Request) {
	f, _, _ := r.FormFile("photo")
	b, _ := io.ReadAll(f)
	err := ioutil.WriteFile("/..", b, 0777)
	if err != nil {
		fmt.Println("失败")
	}
}

<a href="download?filename=file.png">点击我下载</a>

func download(w http.ResponseWriter, r *http.Request) {
	name := r.FormValue("filename")
	ReadFile, _ := os.ReadFile("地址" + name)
	h := w.Header()
	h.Set("Content-Type", "application/octet-stream")
	h.Set("Content-Disposition", "attachment; filename=photo")
	fmt.Fprintln(w, ReadFile)
}

type myStruct struct{}
func (m myStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) {}
func main() {
	// 无论访问什么，结果都一样
	s := http.Server{
		Addr:    "localhost:8888",
		Handler: myStruct{},
	}
}

func Test(w http.ResponseWriter, r *http.Request) {}
func main() {
	// 无论访问什么，结果都一样
	server := http.Server{
		Addr: "localhost:8888",
	}
	http.HandleFunc("url", Test)
	server.ListenAndServe()
}