PHP - Select Query Problem

I need to convert the following select statement to a pdo->query but have no idea how to get it working:

SELECT t.id FROM 
  ( SELECT g.* 
    FROM location AS g
    WHERE g.start <=  16785408
    ORDER BY g.start DESC, g.end DESC
    LIMIT 1
  ) AS t
WHERE t.end >= 16785408;

Here's the code I'm trying:

<?php

$php_scripts = '../../php/';
require $php_scripts . 'PDO_Connection_Select.php';
require $php_scripts . 'GetUserIpAddr.php';
function mydloader($l_filename=NULL)

{
$ip = GetUserIpAddr();
if (!$pdo = PDOConnect("foxclone_data"))
{    
    exit;
}
    if( isset( $l_filename ) ) {  
        $ext = pathinfo($l_filename, PATHINFO_EXTENSION);
        $stmt = $pdo->prepare("INSERT INTO download (address, filename,ip_address) VALUES (?, ?, inet_aton('$ip'))");
        $stmt->execute([$ip, $ext]) ; 

        $test = $pdo->prepare("SELECT t.id FROM ( SELECT g.id FROM lookup AS g WHERE g.start <= inet_aton($ip) ORDER BY g.start DESC, g.end DESC ) AS  t  WHERE t.end >=inet_aton($ip)");
        $test ->execute() ; 
        $ref = $test->fetchColumn();
        $ref = intval($ref);

        $stmt = $pdo->prepare("UPDATE download SET ref = '$ref' WHERE address = '$ip'");
        $stmt->execute() ;         

        header('Content-Type: octet-stream');
        header("Content-Disposition: attachment; filename={$l_filename}");
        header('Pragma: no-cache');
        header('Expires: 0');        
        readfile($l_filename);
       }
        
    else {
        echo "isset failed";
        }  
}
mydloader($_GET["f"]);
exit;

 It gives the following error:

Fatal error: Uncaught PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '.144.181) ORDER BY g.start DESC, g.end DESC ) AS  t  WHERE t.end >=inet_aton(7' at line 1 in /home/foxclone/test.foxclone.com/download/mydloader.php:19 Stack trace: #0 /home/foxclone/test.foxclone.com/download/mydloader.php(19): PDO->prepare('SELECT t.id FRO...') #1 /home/foxclone/test.foxclone.com/download/mydloader.php(38): mydloader('foxclone40a_amd...') #2 {main} thrown in /home/foxclone/test.foxclone.com/download/mydloader.php on line 19

How do I fix this?

<?php

    include("connect.php");

?>
<?php

    echo "<h1>The Hashtag: </h1>";
    if(isset($_GET['hashtag'])){
        echo $_GET['hashtag'];
    }


    // Select the ID of the given hashtag from the "hashtags" table.
    $tqs = "SELECT `id` FROM `hashtags` WHERE `hashtag` = '" . $_GET['hashtag'] . "'";
    $tqr = mysqli_query($dbc, $tqs) or die(mysqli_error($dbc));
    $row = mysqli_fetch_assoc($tqr);

    // This prints e.g.:
    // 100
    echo "<br/><br/>";
    print_r($row['id']);

    // Select the threads from the "thread" table which contains the hashtag ID number.
    $tqs_two = "SELECT * FROM `thread` WHERE `hashtag_id` IN ('" . $row['id'] . "')";
    $tqr_two = mysqli_query($dbc, $tqs_two) or die(mysqli_error($dbc));
    $row_two = mysqli_fetch_assoc($tqr_two);

    echo "<br/><br/>";
    print_r($row_two);

?>

98, 99, 100

<?php
$query1 = DB::getInstance()->query("SELECT c1.id, c1.title, c1.time, c1.removed1, c1.removed2, count(c2.id) AS reps, 
                    m.id as memberid, m.username m.member_first_name, m.member_last_name
                    FROM conversation as c1, conversation as c2, members as m
                    WHERE ((c1.member1='{$logid}' AND c1.read1='No' AND c1.removed1='No'
                    AND m.id=c1.member2)
                    OR (c1.member2='{$logid}' AND c1.read2='No' AND c1.removed2='No'
                    AND m.id=c1.member1))
                    AND c1.id2='1' AND c2.id=c1.id
                    GROUP BY c1.id
                    ORDER BY c1.id DESC");
$query2 = DB::getInstance()->query("SELECT c1.id, c1.title, c1.time, c1.removed1, c1.removed2, count(c2.id) as reps, 
                    m.id as memberid, m.username, m.member_first_name, m.member_last_name
                    FROM conversation as c1, conversation as c2, members as m
                    WHERE ((c1.member1='{$logid}' AND c1.read1='Yes' AND c1.removed1='No'
                    AND m.id=c1.member2)
                    OR (c1.member2='{$logid}' AND c1.read2='Yes' AND c1.removed2='No' AND
                    m.id=c1.member1))
                    AND c1.id2='1' AND c2.id=c1.id
                    GROUP BY c1.id
                    ORDER BY c1.id DESC");
?>

UNREAD MESSAGES (<?php echo intval($query1->count()); ?>)
<br>
READ MESSAGES (<?php echo intval($query2->count()); ?>)