How Can I Add an ELSE to My WHILE Loop?

Below is a simplified segment of my code. How can I add an ELSE to it?

$sql = "SELECT * FROM tadv, tcat, tc 
WHERE tc.advid=tadv.advid 
AND tc.catid=tcat.catid"; 

$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);  
   
while($row = mysql_fetch_assoc($result))

{
echo "<table>";
echo "<tr>";
echo "<td>" . $row['one'] . "</td>";
echo "<td>" . $row['two'] . "</td>";
echo "</tr>";
echo "</table>";
}

PHP:

I tried the following but it didn't work:

$sql = "SELECT * FROM tadv, tcat, tc 
WHERE tc.advid=tadv.advid 
AND tc.catid=tcat.catid"; 

$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);  
   
while($row = mysql_fetch_assoc($result)) 
{
if(!$row) 
{
echo "No matches found!";
}
else 
{
echo "<table>";
echo "<tr>";
echo "<td>" . $row['one'] . "</td>";
echo "<td>" . $row['two'] . "</td>";
echo "</tr>";
echo "</table>";
}
}

PHP:

Any help will be rewarded with reputation points.

 

$sql = "SELECT * FROM tadv, tcat, tc
WHERE tc.advid=tadv.advid
AND tc.catid=tcat.catid";

$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR); 

if(mysql_num_rows($result) < 1){


echo "No matches found!";

}else{
   
while($row = mysql_fetch_assoc($result))
{

echo "<table>";
echo "<tr>";
echo "<td>" . $row['one'] . "</td>";
echo "<td>" . $row['two'] . "</td>";
echo "</tr>";
echo "</table>";
}
}

PHP:

 

Thanks, PHP-lover! It worked.

As promised, I added points to your account.

 

I'm glad it's work, thanks for the rep..