Unusual table output from mysql php - php

Question

Why am I getting those extra layers in the table output? I need to remove those extra layers from the table.What am I doing wrong? What is going on here exactly? Updated code.
<?php
$con=mysqli_connect("localhost","root", "", "cop");
if (mysqli_connect_errno()){
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql= mysqli_query ($con, "SELECT FirstName, Practice FROM Members");
echo "
<style>th {
font: bold 11px 'Trebuchet MS', Verdana, Arial, Helvetica,
sans-serif;
color: #6D929B;
border-right: 1px solid #C1DAD7;
border-bottom: 1px solid #C1DAD7;
border-top: 1px solid #C1DAD7;
letter-spacing: 2px;
text-transform: uppercase;
text-align: left;
padding: 6px 6px 6px 12px;
background: #CAE8EA url(images/bg_header.jpg) no-repeat;
}
th.nobg {
border-top: 0;
border-left: 0;
border-right: 1px solid #C1DAD7;
background: none;
}</style>
<table border='1'>
<tr>
<th>FirstName</th>
<th>Practice</th>
</tr>";
while($row = mysqli_fetch_array($sql))
{
echo "<tr>";
echo "<td>" . $row['FirstName'] . "</td>";
echo "<td>" . $row['Practice'] . "</td>";
echo "</tr>";
}
echo "</table>";
Unusual Table output

Answer 1

If you were to do something like this you would be able to tell if there were empty column values in the data
while( $row = mysqli_fetch_array($sql) ){
if( !empty( $row['FirstName'] ) && !empty( $row['Practice'] ) ){
$firstname=$row['FirstName'];
$practice=$row['Practice'];
} else{
$firstname=$practice='empty';
}
echo "
<tr>
<td>{$firstname}</td>
<td>{$practice}</td>
</tr>";
}
Alternatively just output the row if it is known to contain values rather than having empty cells
while( $row = mysqli_fetch_array($sql) ){
if( !empty( $row['FirstName'] ) && !empty( $row['Practice'] ) ){
$firstname=$row['FirstName'];
$practice=$row['Practice'];
echo "
<tr>
<td>{$firstname}</td>
<td>{$practice}</td>
</tr>";
}
}

Answer 2

I pasted your code on my Notepad++ and in it were errors which the browser cannot forgive. In fact you can even receive a 1 month suspended sentence from your browser. Below is my version of your code. I have ignored the style. You can add style after the code is working.
<?php
$con=mysqli_connect("localhost","root", "", "cop");
if (mysqli_connect_errno()){
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql= mysqli_query($con, "SELECT FirstName, Practice FROM Members");
$result = '';
if(mysqli_num_rows($sql) > 0){
while($row = mysqli_fetch_array($sql)){
$FirstName = $row['FirstName'];
$Practice = $row['Practice'];
$result .= "<tr><td>" . $FirstName . "</td><td>" . $Practice . "</td></tr>";
}
}
if(isset($result)){
echo "<table border='1'>";
echo "<tr><th>FirstName</th><th>Practice</th></tr>";
echo $result;
echo "</table>";
}
?>