PHP - Join And Use Unique Data From Same Column Names

<?
include('connect_visits.php');
doDB7();
$limitStart = $_POST['QUARTER'] - 13;
$Visit_data="SELECT Visits.ID, Visits.WVisits, Visits.WCom, WeekNo.WNo, WeekNo.WCom
        FROM Visits 
        LEFT JOIN WeekNo
            ON Visits.ID = WeekNo.WCom
        ORDER BY Visits.ID
	 LIMIT {$limitStart}, 13";
$Visit_data_res = mysqli_query($mysqli, $Visit_data) or die(mysqli_error($mysqli));
$display_block = "
<table width=\"20%\" cellpadding=\"3\" cellspacing=\"1\" border=\"1\" BGCOLOR=\"white\" >
	<tr>
	<th>Week No</th>
	<th>Week Commencing</th>
	<th>Visits</th>
		</tr>";	
while ($C_info = mysqli_fetch_array($Visit_data_res)) {
		$Cid = $C_info['ID'];
		$Visits = ($C_info['WVisits']);
		$WeekNo = ($C_info['WCom']);
//add to display
$display_block .= "
<tr>
<td width=\"1%\" valign=\"top\">".$Cid."<br/></td>
<td width=\"8%\" valign=\"top\">".$WeekNo."<br/></td>
<td width=\"5%\" valign=\"top\">".$Visits."<br/></td>
</td></tr>";
}
mysqli_free_result($Visit_data_res);
?>

$sql = "SELECT b.id, b.title, b.author, b.isbn, b.publicationYear,
        c.cat_name
        FROM book AS b
        INNER JOIN category AS c ON b.category = c.id
        WHERE status != 'Archive' ORDER BY id DESC LIMIT $startrow, 15 ";


$res = $conn->query($sql) or trigger_error($conn->error."[$sql]");


while($row = $res->fetch_array()) {


    echo '<tbody>';
    echo '<tr>';
    echo '<td>' . $row['id'] . '</td>';
    echo '<td>' . $row['title'] . '</td>';
    echo '<td>' . $row['author'] . '</td>';
    echo '<td>' . $row['cat_name'] . '</td>';
    echo '<td>' . $row['isbn'] . '</td>';
    echo '<td>' . $row['publicationYear'] . '</td>';
    echo '</tr>';
    echo '</tbody>';
};

i'm doing my best to research this stuff guys, but I keep getting stuck.  My reporting is almost finished, but I'm stuck at the part of my code that's denoted by "//FOR EACH LOOP HERE?"  Can someone help?  in addition to this missing code I need, I also get the error "mysqli_num_rows() expects parameter 1 to be mysqli_resul".  But all these examples on the web use pretty much the same code like this.

<?php

$dbHost = "localhost";
$dbName= "rptDatabase";
$dbUsername = "username";
$dbPassword = "password";

	$conn = mysqli_connect($dbHost, $dbUsername, $dbPassword, $dbName);

	if (mysqli_connect_errno()) {
		echo "Failed to connect to MySQL: " . mysqli_connect_error();
								}
	$sql = mysqli_query($conn, "SELECT * FROM tblTraffic ORDER BY ip, date, time"); 
	$report = mysqli_fetch_array($sql); 

echo "<table border='1'>
<tr>
<th>IP ADDRESS</th>
<th>PAGE VISITED</th>
<th>PREVIOUS PAGE</th>
<th>DATE</th>
<th>TIME</th>
</tr>";

	if (mysqli_num_rows($report) > 0) {
		while($row = mysqli_fetch_array($report)) {
	    	echo "<tr>";
	    	//FOR EACH LOOP HERE?
    									 	 	  }
							   		  }
    else {
    	echo "0 results";
		 }

	$conn->close();

?>

I have some php code on view invoice and it's getting all the data I need to from three database tables but for some reason it's not getting the data for one specific column and unsure why

I have done a echo sql and it is echoing the sql query ok and have ran the sql query in phpmyadmin and is displaying the column in phpmyadmin that is not displaying on the php page so am bit confused, below is the coding I have. I took out a lot of it and tried to keep to the relevant parts

<?php
$sql = "SELECT t1.id, t1.invoice_number, DATE_FORMAT(t1.invoice_date,'%d/%m/%Y') AS invoice_date, t1.user_id, t2.invoice_number, t2.service_name, t2.service_price, t3.user_id, t3.customer_name, t3.customer_phone, t3.customer_email, t2.service_name, t2.service_price, t1.invoice_total, t1.balance, t1.notes, DATE_FORMAT(t1.payment_date,'%d/%m/%Y') AS payment_date, t1.payment_method
FROM invoices as t1
LEFT JOIN invoice_products as t2
ON t1.id = t2.invoice_id
LEFT JOIN users as t3
ON t1.user_id = t3.user_id
WHERE t1.user_id = '".$_SESSION['user_id']."' and t1.id = '".$_GET['id']."'";

$result = mysqli_query($connect, $sql);

                if(mysqli_num_rows($result) > 0)
                {
                if($row = mysqli_fetch_array($result))  
                {
                ?>

                Notes: <?php echo $row['notes'];?>

                <?php
                    }
                    }
                    ?>