PHP require_once抛出“Undefined Class Constant”错误

Question

The code below is supposed to use class data setup in sqlClass.php, but I am getting an "Undefined class constant 'getHost' error when running the script. Should I be putting the require_once somewhere else if it's being used within a function?

getHost, getSqlUser, and getSqlPassword are defined in sqlClass.php

<?php
use CallFire\Api\Rest\Request;
use CallFire\Api\Rest\Response;
require 'autoload.php';
require_once('shannonTeslaApiKey.php');
require_once('sqlClass.php');


/*creates executeSql function, which opens connection to db and inserts orderId into order_verify table */
function addRowToVerifyOrder($anOrderNumber, $aStatus, $someDIDs) {

    $dbConnection = mysql_connect(CallFireSqlTokens::getHost, CallFireSqlTokens::getSqlUser, CallFireSqlTokens::getSqlPassword)
    or die('Could not connect: ' . mysql_error());
    mysql_select_db('opsnumberorder') or die('Could not select database');

    $someSql = 'INSERT INTO verify_order VALUES('. $anOrderNumber .', "'. $aStatus .'", now(), '. $someDIDs .')';
    /*DEBUGGING TOOL
    echo "sql is " . $someSql;*/

    $result = mysql_query($someSql) or die('Query failed: ' . mysql_error());

    //mysql_free_result($result);
    mysql_close($dbConnection);

    return $result;
}