PHP函数连接数据库调用查询失败

Question

我有三个.php 文件。

db_conx.php

$db_conx = mysqli_connect("localhost", "admin", "admin", "gestiune");
    // Evaluate the connection
    if (mysqli_connect_errno()) {
        echo mysqli_connect_error();
        exit();
}

functions.php

function deplata($pid){
        $sqlp = "SELECT * FROM plati WHERE user_id";
        $queryp = mysqli_query($db_conx, $sqlp);
        $type = "day";
        $payments = 0;
        $salary = 80;
        $days = 4;
        $topay = 0;
        while($getplata = mysqli_fetch_assoc($queryp)){
            $plati += $getplata['valoare'];
        }
        if($tip == "day"){
            $topay = $days * $salary;
        }

        return $topay;
}

我有 index.php 文件来调用这些文件并使用它们。

include_once("php_includes/db_conx.php");
include_once("php_includes/functii.php");

$salariu = deplata(5);
echo $salariu;

问题是它无法连接到数据库并返回一些错误：

注意：未定义变量：db_conx in D:\xampp\htdocs\manager\pages\php_includes\functions.php 在第 5 行

警告：mysqli_query() 期望参数 1 为 mysqli，给定 null 在 D:\xampp\htdocs\manager\pages\php_includes\functions.php 第 5 行

警告：mysqli_fetch_assoc() 期望参数 1 为 mysqli_result， D:\xampp\htdocs\manager\pages\php_includes\functions.php 中给出的 null 在第 11 行

然后它打印该值（因为它当前不使用数据库任何值）。 我尝试了什么：我尝试将functions.php 内容直接放入index.php 文件中，我尝试在functions.php 文件中调用db_conx.php 文件。

Answer 1

你需要在function.php.checkout下面的代码中定义值

function.php

function deplata($pid){

   global $db_conx;

    $sqlp = "SELECT * FROM plati WHERE user_id";
    $queryp = mysqli_query($db_conx, $sqlp);
    $type = "day";
    $payments = 0;
    $salary = 80;
    $days = 4;
    $topay = 0;
    while($getplata = mysqli_fetch_assoc($queryp)){
        $plati += $getplata['valoare'];
    }
    if($tip == "day"){
        $topay = $days * $salary;
    }

    return $topay;
}

index.php

检查index.php中的拼写错误

include_once("php_includes/function.php");