If you have added mysql connection in connect_mysql.php than you can't access that MYSQL connection variable inside function without passing it as parameter.
So you need to change your code like below,
<?php
// connect to mysql
include('connect_mysql.php');
// make sure the webservice returns plain text
header( 'Content-Type: text/plain; charset=utf-8' );
// include 3rd party parsing utility
require './vendor/querypath/qp.php';
$gidURL = $_SERVER['REQUEST_URI'];
// figure out which guild to scrape info for
// MAKE SURE TO CHANGE TO EXACT URLS ONCE PAGES ARE COMPLETE
if(strpos($gidURL, 'guild_members') !== false) {
$url = 'https://swgoh.gg/g/21284/gid-1-800-druidia/';
}else if(strpos($gidURL, 'liquid-schwartz') !== false) {
$url = 'https://swgoh.gg/g/19528/gid-liquid-schwartz/';
}else if(strpos($gidURL, 'spaceballsdeep') !== false) {
$url = 'https://swgoh.gg/g/14280/gid-spaceballsdeep/';
}else if(strpos($gidURL, 'chapter-eleven') !== false) {
$url = 'https://swgoh.gg/g/41958/gid-chapter-eleven/';
}else if(strpos($gidURL, 'my-own-best-friend') !== false) {
$url = 'https://swgoh.gg/g/4736/gid-my-own-best-friend/';
}else if(strpos($gidURL, 'gone-to-plaid') !== false) {
$url = 'https://swgoh.gg/g/363/gid-gone-to-plaid/';
}else if(strpos($gidURL, 'my-schwartz-is-bigger') !== false) {
$url = 'https://swgoh.gg/g/27827/gid-my-schwartz-is-bigger/';
}else if(strpos($gidURL, 'ludicrousspeed') !== false) {
$url = 'https://swgoh.gg/g/19538/gid-ludicrousspeed/';
}else if(strpos($gidURL, 'lone-starr') !== false) {
$url = 'https://swgoh.gg/g/32650/gid-lone-starr/';
}else {
echo "No guild was found in the URL.
";
}
// get the HTML page into the parser
$guild_page = htmlqp( $url );
// $guild_page = htmlqp( './test-druidia.html' ); // for testing if you don't want to hit swgoh.gg
function guild_info_data($dbcon) {
// init empty array that will hold our data later
$guild_members = [];
global $guild_page;
// loop through table rows
foreach ( $guild_page -> find( '.character-list tbody tr' ) as $row ) {
// init empty array for individual player
$guild_member = [];
$member_name = [];
$member_gp = [];
$member_cs = [];
$member_rank = [];
$member_rank_avg = [];
// store data in temporary array
$guild_member[ 'name' ] = preg_replace( "/|
/", "", trim( $row -> branch( 'td' ) -> eq( 0 ) -> text() ) );
$guild_member[ 'gp' ] = $row -> branch( 'td' ) -> eq( 1 ) -> text();
$guild_member[ 'collection_score' ] = $row -> branch( 'td' ) -> eq( 2 ) -> text();
$guild_member[ 'arena_rank' ] = $row -> branch('td') -> eq(3) -> text();
$guild_member[ 'arena_average' ] = $row -> branch( 'td' ) -> eq( 4 ) -> text();
// add player array to full response array
$guild_members[] = $guild_member;
}
foreach ($guild_members as $guild_member) {
$member_name[] = $guild_member['name'];
}
foreach ($guild_members as $guild_member) {
$member_gp[] = $guild_member['gp'];
}
foreach ($guild_members as $guild_member) {
$member_cs[] = $guild_member['collection_score'];
}
foreach ($guild_members as $guild_member) {
$member_rank[] = $guild_member['arena_rank'];
}
foreach ($guild_members as $guild_member) {
$member_rank_avg[] = $guild_member['arena_average'];
}
}
// check what page is loaded
if(strpos($gidURL, 'guild_members') !== false) {
$name_insert = "INSERT INTO gid-1-800-druidia (name, galactic_power, collection_score, arena_rank, arena_average) VALUES ('$member_name', '$member_gp', '$member_cs', '$member_rank', '$member_rank_avg')";
try{
mysqli_query($dbcon, $name_insert);
}catch (mysqli_sql_exception $e) {
echo $e->getMessage();
}
}else if(strpos($gidURL, 'liquid-schwartz') !== false) {
// insert LSD data
}else if(strpos($gidURL, 'spaceballsdeep') !== false) {
// insert SBD data
}else if(strpos($gidURL, 'chapter-eleven') !== false) {
// insert C11 data
}else if(strpos($gidURL, 'my-own-best-friend') !== false) {
// insert MOBF data
}else if(strpos($gidURL, 'gone-to-plaid') !== false) {
// insert GtP data
}else if(strpos($gidURL, 'my-schwartz-is-bigger') !== false) {
// insert SCH data
}else if(strpos($gidURL, 'ludicrousspeed') !== false) {
// insert LS data
}else if(strpos($gidURL, 'lone-starr') !== false) {
// insert LST data
}else {
echo "No guild info was pulled.";
}
// let's get out of here
exit;
?>