問題描述

我正在嘗試為我的網站構建一些功能，其中一些包括從mysql數據庫中獲取數據.當我在函數之外測試代碼時它似乎工作正常.所以在這里，第一頁:

I'm tryin to build some functions for a website of mine and some of them consist in fetching data from the mysql database. When I test the code outside of the function it seems to work properly. So here it is, The first page:

require('db.php');
require('functions.php');

$email = 'sample@gmail.com';

if (user_exists($email) == true){
 echo "Good news, this exists";
}

現在 db.php :

Now db.php :

$db = new MySQLi("localhost","test","test","test");
if ($db->connect_errno){
    echo "$db->connect_errno";
}

還有functions.php文件:

And the functions.php file:

function sanitize ($data){
    $db->mysqli_real_escape_string($data);
}
function user_exists($usermail){
    $usermail = sanitize($usermail);
    $query = $db->query("SELECT COUNT(userId) FROM users WHERE userEmail= '$usermail' ");
    $check = $query->num_rows;
    return ($check == 1) ? true : false;
}

訪問第一個文件時遇到的錯誤是:

And the error I'm getting when accessing the first file is:

Notice: Undefined variable: db in C:xampphtdocsauctiorincfunctions.php on line 6

Fatal error: Call to a member function query() on a non-object in C:xampphtdocsauctiorincfunctions.php on line 6

所以我需要/包含了 db.php，其中 $db 是 mysqli 連接.在同一個文件(第一個文件)中，我調用位于 functions.php 的函數

SO I've required/included the db.php where $db is the mysqli connect. And within the same file(first file) I call the functions located at functions.php

先謝謝你，我很感激你的幫助，因為這讓我很生氣......

Thank you in advance, I'd appreciate your help as this is pissing me off......

推薦答案

你可能需要使用 global 關鍵字，否則 $db 被認為是局部范圍內的 var.

You probably need to use the global keyword, otherwise $db is considered a var in local scope.

function sanitize ($data){
    global $db;
    $db->mysqli_real_escape_string($data);
}

function user_exists($usermail){
    global $db;
    $usermail = sanitize($usermail);
    $query = $db->query("SELECT COUNT(userId) FROM users WHERE userEmail= '$usermail' ");
    $check = $query->num_rows;
    return ($check == 1) ? true : false;
}

這篇關于函數內部的 mysqli/mysql 查詢不起作用的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！