Question

这个问题自2周以来一直令我担忧。

代码： -

<?php
session_start();
include '../dbconnector.php';

function getRandUsername()
{
    include '../dbconnector.php';
    $u = rand(0,99999);
    //check if the number exists in the database already
    $query="SELECT * from admin where username = '" . $u . "'";
    $result=mysql_query($query,$db) or die (mysql_error($db));
    if(mysql_num_rows($result) > 0)
    {
        echo "Username Exists";
        getRandUsername();
        exit();
    }
    else
    {
        echo "Username Does not exist";
    }
}

getRandUsername();

?>

问题： - 问题是，我需要两次包含此 dbconnector.php 文件。如果我不在函数括号中包含它，则会抛出错误。如果文件包含在功能块中，则一切正常。

这里有什么问题？

感谢。

Answer 1

尝试以下方法：

require_once '../dbconnector.php';

function getRandUsername() {
    global $db;    // where I'm assuming that $db is defined in the external file

Answer 2

从我在代码中看到的内容，您永远不会定义$db所以我认为它是在dbconnector.php文件中定义的。在这种情况下，由于您是从function之外设置的，因此您可以执行以下两项操作之一：

将其设置为全局变量：

<?php
session_start();
include '../dbconnector.php';
$GLOBALS['db'] = $db; //Sets it as global

function getRandUsername()
{
    $db = $GLOBALS['db'] //Receives it as global
    include '../dbconnector.php';
    $u = rand(0,99999);
    //check if the number exists in the database already
    $query="SELECT * from admin where username = '" . $u . "'";
    $result=mysql_query($query,$db) or die (mysql_error($db));
    if(mysql_num_rows($result) > 0)
    {
        echo "Username Exists";
        getRandUsername();
        exit();
    }
    else
    {
        echo "Username Does not exist";
    }
}

getRandUsername();

?>

在函数调用中设置它：

<?php
session_start();
include '../dbconnector.php';

function getRandUsername($db)
{
    include '../dbconnector.php';
    $u = rand(0,99999);
    //check if the number exists in the database already
    $query="SELECT * from admin where username = '" . $u . "'";
    $result=mysql_query($query,$db) or die (mysql_error($db));
    if(mysql_num_rows($result) > 0)
    {
        echo "Username Exists";
        getRandUsername();
        exit();
    }
    else
    {
        echo "Username Does not exist";
    }
}

getRandUsername($db); //Passes the value to the function

?>

需要两次添加配置文件

2 个答案: