PHP函数连接数据库调用查询失败

Question

我有三个 .php 个文件。

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且 returns 一些错误：

Notice: Undefined variable: db_conx in D:\xampp\htdocs\manager\pages\php_includes\functions.php on line 5

Warning: mysqli_query() expects parameter 1 to be mysqli, null given in D:\xampp\htdocs\manager\pages\php_includes\functions.php on line 5

Warning: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given in D:\xampp\htdocs\manager\pages\php_includes\functions.php on line 11

然后打印值（因为它当前不使用数据库的任何值）。我尝试了什么：我试图将 functions.php 内容直接放入 index.php 文件中，我试图在 functions.php 文件中调用 db_conx.php 文件。

Answer 1

您需要在 function.php 中定义值。查看下面的代码

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

中的错别字

include_once("php_includes/function.php");

PHP函数连接数据库调用查询失败

PHP function fails to connect to the database to call query

php

mysql

mysqli