从Golang API远程访问OVH SQL数据库

huangapple go评论96阅读模式
英文:

Remote access OVH SQL database from Golang API

问题

我正在制作一个用于与我的Android应用程序中的SQL数据库进行交互的Golang API。我遇到的问题是:

我有一个托管在https://phpmyadmin.ovh.net/上的SQL数据库。

我正在尝试将我的本地API连接到这个数据库。根据文档:

func Open(driverName, dataSourceName string) (*DB, error)

driverName参数应该是"mysql",对吗?
但是,dataSourceName参数应该是什么?

我看到了很多关于Open的帖子,但是我不认为我理解如何组织关于dataSourceName参数的URL字符串。

谢谢阅读和帮助!

编辑:

根据你们两个的回答,我尝试了下面的代码:

package main

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

type databaseinfos struct {
    user string
    password string
    name string
    address string
    port string
    url string
}

var db *sql.DB // 全局变量,用于在main和HTTP处理程序之间共享
var dbi *databaseinfos

func main() {

    dbi := databaseinfos{
	    user: "Emixam23",
	    password: "",
	    name: "mydb",
	    address: "127.0.0.1",
	    port: "3306",
	    url: ""}
    dbi.url = (dbi.user + ":" + dbi.password + "@tcp(" + dbi.address + ":" + dbi.port + ")/" + dbi.name)

    fmt.Println(dbi.url)

    db, err := sql.Open("mysql", dbi.url)
    if err != nil {
        fmt.Println("Error on initializing database connection: %s", err.Error())
    }

    err = db.Ping()
    if err != nil {
        fmt.Println("Error on opening database connection: %s", err.Error())
    }

    /*http.HandleFunc("/", hello)*/
    http.ListenAndServe(":8080", nil)
}

然而,我遇到了一个错误,错误信息是"Error on opening database connection: %s dial tcp 127.0.0.1:3306: connectex: No connection could be made because the target machine actively refused it."。

这个问题是由于我的计算机还是由于dataSourceName参数引起的?

英文:

I'm making a Golang API to be able to interact with a SQL database from my Android application. The problem I have is the following:

I have a sql database hosted on https://phpmyadmin.ovh.net/

I'm trying to connect my locale API to this one. According to the documentation:

func Open(driverName, dataSourceName string) (*DB, error)

The driverName params would be "mysql" isn't it?
But, what would be the dataSourceName params?

I saw lot of post about Open, however, I don't think I understand how to organize the url string about the dataSourceName params.

package main

import (
    "net/http"
    "database/sql"
    "fmt"
)

var db *sql.DB // global variable to share it between main and the HTTP handler

func main() {

fmt.Println("starting up")

db, err := sql.Open("mysql", "????????????")
if err != nil {
    fmt.Println("Error on initializing database connection: %s", err.Error())
}

err = db.Ping()
if err != nil {
    fmt.Println("Error on opening database connection: %s", err.Error())
}

http.HandleFunc("/", hello)
http.ListenAndServe(":8080", nil)
}

Thank for read & help !

/!\ EDIT /!\

So, after your both answers, I tried the code below:

package main

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

type databaseinfos struct {
user string
password string
name string
address string
port string
url string
}

var db *sql.DB // global variable to share it between main and the HTTP handler
var dbi *databaseinfos

func main() {

dbi := databaseinfos{
	user: "Emixam23",
	password: "",
	name: "mydb",
	address: "127.0.0.1",
	port: "3306",
	url: ""}
dbi.url = (dbi.user + ":" + dbi.password + "@tcp(" + dbi.address + ":" + dbi.port + ")/" + dbi.name)

fmt.Println(dbi.url)

db, err := sql.Open("mysql", dbi.url)
if err != nil {
    fmt.Println("Error on initializing database connection: %s", err.Error())
}

err = db.Ping()
if err != nil {
    fmt.Println("Error on opening database connection: %s", err.Error())
}

/*http.HandleFunc("/", hello)*/
http.ListenAndServe(":8080", nil)
}

However, I got an error which is "Error on opening database connection: %s dial tcp 127.0.0.1:3306: connectex: No connection could be made because the target machine actively refused it.".

Does the problem comes because of my computer or because of the dataSourceName params?

答案1

得分: 1

dataSourceName 应该以 DSN 格式提供:

<username>:<password>@tcp(<host>:<port>)/<database>

例如:

db, err := sql.Open("mysql", "myuser:password@tcp(127.0.0.1:3306)/mydb")
英文:

dataSourceName should be provided in the DSN format:

&lt;username&gt;:&lt;password&gt;@tcp(&lt;host&gt;:&lt;port&gt;)/&lt;database&gt;

For example:

db, err := sql.Open(&quot;mysql&quot;, &quot;myuser:password@tcp(127.0.0.1:3306)/mydb&quot;)

答案2

得分: 0

你的代码中有一个问题,就在这里:

dbi.url = (dbi.user + ":" + dbi.password + "@tcp(...

根据我看到的参数,用这种方式构建连接字符串会得到:

Emixam23:@tcp..

这是一个空密码,根据规范来看是错误的:

[username[:password]@][protocol[(address)]]/dbname[?param1=value1&...&paramN=valueN]

我们可以看到,如果不需要密码,就不要添加 ":"。

如果问题仍然存在,并且连接字符串实际上与正确的模式匹配,请测试是否可以访问你的数据库:

mysql -u Emixam23

或者使用密码:

mysql -u Emixam23 -p

然后尝试访问数据库,看看你的用户是否具有适当的权限:

> USE mydb; SELECT 1;

如果你甚至无法连接:

检查你的端口和IP绑定是否正确:

sudo netstat -antp | grep mysql

如果不正确,请相应地编辑 /etc/mysql/my.cnf

英文:

There's a problem in your code, here:

dbi.url = (dbi.user + &quot;:&quot; + dbi.password + &quot;@tcp(...

This way of building the connection string with the parameters I see above will result in:

Emixam23:@tcp...

With an empty password, which is wrong if we look at the spec:

[username[:password]@][protocol[(address)]]/dbname[?param1=value1&amp;...&amp;paramN=valueN]

We see that if no password is required you must not add the ":"

If the problem persists and the connection string actually matches the correct pattern, test that you can access your DB:

mysql -u Emixam23

or with password:

mysql -u Emixam23 -p

Then try to access the database to see if your user has the proper pemissions:

&gt; USE mydb; SELECT 1;

If you can't even connect:

Check that your port and IP binding are correct:

sudo netstat -antp | grep mysql

If not, edit your /etc/mysql/my.cnf accordingly.

huangapple
  • 本文由 发表于 2016年3月8日 18:49:53
  • 转载请务必保留本文链接:https://go.coder-hub.com/35865356.html
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