Question

我正在学习GoLang web开发，我正在尝试一个简单的例子，在使用Golang模板渲染的网页上显示mysql数据库中的表。下面是我的代码片段，它不起作用。表格渲染失败，其中范围功能在模板无法正常工作

Server.go

package main

import (
    "fmt"
    "net/http"
    _ "github.com/go-sql-driver/mysql"
    "database/sql"
    "os"
    "html/template"
)

type Employee struct {
    fname, sname, dname, email string
}

func helloWorld(w http.ResponseWriter, r *http.Request){
    name, err := os.Hostname()
    checkErr(err)
    fmt.Fprintf(w, "HOSTNAME : %s\n", name)
}

func dbConnect() (db *sql.DB) {
    dbDriver := "mysql"
    dbUser := "root"
    dbPass := "password"
    dbHost := "mysql.go"
    dbPort := "3306"
    dbName := "company"
    db, err := sql.Open(dbDriver, dbUser +":"+ dbPass +"@tcp("+ dbHost +":"+ dbPort +")/"+ dbName +"?charset=utf8")
    checkErr(err)
    return db
}

func dbSelect() []Employee{
    db := dbConnect()
    rows, err := db.Query("select * from employees")
    checkErr(err)

    employee := Employee{}
    employees := []Employee{}

    for rows.Next() {
        var first_name, last_name, department, email string
        err = rows.Scan(&first_name, &last_name, &department, &email)
        checkErr(err)
        employee.fname = first_name
        employee.sname = last_name
        employee.dname = department
        employee.email = email
        employees = append(employees, employee)

    }
    defer db.Close()
    return employees
}

var tmpl = template.Must(template.ParseFiles("layout.html"))
//var tmpl = template.Must(template.ParseGlob("layout.html"))
func dbTableHtml(w http.ResponseWriter, r *http.Request){
    table := dbSelect()
    tmpl.ExecuteTemplate(w, "Index", table)
}

func dbTable(w http.ResponseWriter, r *http.Request){
    table := dbSelect()
    for i := range(table) {
        emp := table[i]
        fmt.Fprintf(w,"YESS|%12s|%12s|%12s|%20s|\n" ,emp.fname ,emp.sname ,emp.dname ,emp.email)
    }
}

func main() {
    http.HandleFunc("/", helloWorld)
    http.HandleFunc("/view", dbTableHtml) 
    http.HandleFunc("/raw", dbTable)
    http.ListenAndServe(":8080", nil)
}

func checkErr(err error) {
    if err != nil {
        panic(err)
    }
}

的layout.html

{{ define "Index" }}
<!DOCTYPE html>
<html lang="en-US">
    <head>
        <title>Maithanam Website</title>
        <meta charset="UTF-8" />
    </head>
    <body>
        <h1>Maithanammm website for mysql</h1> 

    {{ $length := len . }}
    <h3>Length {{$length}}</h3> 

    <table border="1">
      <tr>
        <td>FirstName</td>
        <td>SecondName</td>
        <td>Department</td>
        <td>Email</td>
      </tr>
    {{ range . }}
      <tr>
        <td>{{ .fname }}</td>
        <td> {{ .sname }} </td>
        <td>{{ .dname }} </td>
        <td>{{ .email }} </td>
      </tr>
    {{ end }}
    </table>

    </body>
</html>
{{ end }}

网页 enter image description here

Answer 1

你有两个问题：

致电ExecuteTemplate时，您没有检查错误。
您的模板使用的是非导出字段，请注意您的第一个问题就是告诉您这个。

对于第一个问题：

err := tmpl.ExecuteTemplate(w, "Index", table)
if err != nil {
    // Do something with the error
}

对于第二个问题，请将struct更改为导出字段：

type Employee struct {
    Fname, Sname, Dname, Email string
}

然后更改模板以使用新的字段名称。

在Golang网站上使用模板显示mysql表

1 个答案: