Wrongly displayed table, row's aren't aligned to each other - php

Question

I have this issue, where I print out every detail of all users, but as you can see on the photo below, they aren't exactly aligned correctly. By that I mean that some firstnames' boxes are only let's say 50pixels wide, but some are wider.
Is there a way to fix this issue, and align each entry's details?
I attached the php code below, so you can have a look at it.
Thanks in advance
while($users=mysqli_fetch_assoc($getUsers)){
echo '<table border="1" cellpadding="1" cellspacing="1" width="80%" style="margin: 0 auto">';
echo '<tr class="allUsers">';
echo '<th>Username</th>';
echo '<th>First name</th>';
echo '<th>Last name</th>';
echo '<th>Email</th>';
echo '<th>Year group</th>';
echo '<th>Subject 1</th>';
echo '<th>Subject 2</th>';
echo "<th>Subject 1's teacher</th>";
echo "<th>Subject 2's teacher</th>";
echo '<th>Privilege</th>';
echo '<th>Own database</th>';
echo '</tr>';
echo '<tr>';
echo '<td>'.$users['username'].'</td>';
echo '<td>'.$users['first_name'].'</td>';
echo '<td>'.$users['last_name'].'</td>';
echo '<td>'.$users['email'].'</td>';
echo '<td>'.$users['year_group'].'</td>';
echo '<td>'.$users['subject'].'</td>';
echo '<td>'.$users['subject2'].'</td>';
echo '<td>'.$users['teacher'].'</td>';
echo '<td>'.$users['teacher2'].'</td>';
echo '<td>'.$users['is_admin'].'</td>';
echo '<td>'.$users['own_database'].'</td>';
echo '</tr>';
echo '</table>';
In addition to all of this, is there a way where I can just display the headers only once at the top, then just list all of the users' details?

Answer 1

You are creating a separate table for each user, when you actually need only one. Try separating the <table> tags and the headers from the loop, so they are only echoed once:
echo '<table border="1" cellpadding="1" cellspacing="1" width="80%" style="margin: 0 auto">';
echo '<tr class="allUsers">';
echo '<th>Username</th>';
echo '<th>First name</th>';
echo '<th>Last name</th>';
echo '<th>Email</th>';
echo '<th>Year group</th>';
echo '<th>Subject 1</th>';
echo '<th>Subject 2</th>';
echo "<th>Subject 1's teacher</th>";
echo "<th>Subject 2's teacher</th>";
echo '<th>Privilege</th>';
echo '<th>Own database</th>';
echo '</tr>';
while($users=mysqli_fetch_assoc($getUsers)){
echo '<tr>';
echo '<td>'.$users['username'].'</td>';
echo '<td>'.$users['first_name'].'</td>';
echo '<td>'.$users['last_name'].'</td>';
echo '<td>'.$users['email'].'</td>';
echo '<td>'.$users['year_group'].'</td>';
echo '<td>'.$users['subject'].'</td>';
echo '<td>'.$users['subject2'].'</td>';
echo '<td>'.$users['teacher'].'</td>';
echo '<td>'.$users['teacher2'].'</td>';
echo '<td>'.$users['is_admin'].'</td>';
echo '<td>'.$users['own_database'].'</td>';
echo '</tr>';
}
echo '</table>';

Answer 2

It looks like every 2 rows is its own table. Make the <tr>'s repeat, not the complete <table>'s.