Google Maps documentation uses deprecated PHP - how can I update it? - php

Question

https://developers.google.com/maps/documentation/javascript/mysql-to-maps
Features deprecated PHP for connecting to a MySQL database, i.e. using mysql instead of mysqli or pdo.
I tried following the tutorial to display markers with set names/lat/lng from a mySQL database, but found that the PHP was deprecated and simply replacing 'mysql' with 'mysqli' gave me a nearly empty XML document.
Here is my PHP:
<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "pins_db";
$database = "root-pins_db";
function parseToXML($htmlStr)
{
$xmlStr=str_replace('<','<',$htmlStr);
$xmlStr=str_replace('>','>',$xmlStr);
$xmlStr=str_replace('"','"',$xmlStr);
$xmlStr=str_replace("'",''',$xmlStr);
$xmlStr=str_replace("&",'&',$xmlStr);
return $xmlStr;
}
// Opens a connection to a MySQL server
$connection=mysqli_connect ('localhost', $username, $password);
// Set the active MySQL database
$db_selected = mysqli_select_db($connection, $dbname);
// Select all the rows in the markers table
$query = "SELECT * FROM pins_table WHERE 1";
$result = mysqli_query($query);
header("Content-type: text/xml");
// Start XML file, echo parent node
echo '<markers>';
// Iterate through the rows, printing XML nodes for each
while ($row = #mysqli_fetch_assoc($result)){
// Add to XML document node
echo '<marker ';
echo 'name="' . $row['name'] . '" ';
echo 'lat="' . $row['lat'] . '" ';
echo 'lng="' . $row['lng'] . '" ';
echo '/>';
}
// End XML file
echo '</markers>';
?>
The resulting XML document only contains:
<markers/>
I'm running PHP 7.0.15 and MySQL 5.6.35 on MAMP.
The database info:
user/pw: root/root
database: pins_db
table: pins_table
The table:
1 id int(11)
2 datetime datetime
3 lat float(10,6)
4 lng float(10,6)
5 name text
Am I missing something here? I'm fairly new to PHP and very new to mySQL; I can't find an answer to this anywhere else online.

Answer 1

Turn on php error reporting
error_reporting(E_ALL);
ini_set('display_errors', 1);
http://php.net/manual/en/function.error-reporting.php
http://php.net/manual/en/function.ini-set.php
Test for successful execution of the query execution.
$result = mysqli_query($connection,$query);
if(!$result) {
// error returned
die('error#002: '.mysqli_error($connection));
}
http://php.net/manual/en/mysqli.error.php
Remove the # (at sign) before the function call, because we do not want to silence php errors:
while ( $row = #mysqli_fetch_assoc($result) ) {
^
Also check for a successful connection
$connection = mysqli_connect('localhost', $username, $password);
if(!$connection) {
die('error connecting: ' . mysqli_connect_error());
}
http://php.net/manual/en/mysqli.connect-error.php
It's also possible that mysqli_select_db isn't working. For example if the database name is incorrect or doesn't exist.
http://php.net/manual/en/mysqli.select-db.php
Note that a database name could be supplied as a fourth argument on mysqli_connect.
https://ericlippert.com/2014/03/05/how-to-debug-small-programs/