Can't pass form data to PHP to update Database - php

Question

Thanks to all who responded. I got it to update with a combination of ideas from you. I've amended the code to show what's working.
To implement LIKE functionality by passing the LIKE button value to php so as to update the DB.
This displays the table, complete with a LIKE button per row:
echo '<table>
<tr>
<th>Word ID</th>
<th>User ID</th>
<th>User Name</th>
<th>Word</th>
<th>Meaning</th>
<th>Example</th>
</tr>';
foreach ($data as $row)
{
echo '<tr>';
foreach ($row as $value)
{
echo '<td>';
echo $value;
echo '</td>';
}
echo '<td>
<form method="POST" action="'.$_SERVER["PHP_SELF"].'">
<input type="hidden" name="LIKE" value="'.$row['wordID'].'">
<input type="submit" class="btn btn-success" value="Submit">
</form>
</td>';
echo '</tr>';
}
echo '</table>';
The code to process the form submit is:
if($_POST['submit'])
{
$sql = "UPDATE vocab SET likes = likes+1 where wordID = '{$row['wordID']}'";
$stmt = $db->prepare($sql);
/* Execute */
$stmt->execute();
}

Answer 1

<form method="post" action="<?php echo $_SERVER["PHP_SELF"]?>
is a sytax you use when you are NOT already in a <?php tag. Here, you already are writing in PHP and in an echo and you just apen again a <?php, and another echo in it, this makes no sense.
echo '... <form method="post" action="'.$_SERVER["PHP_SELF"].'"> ...';
is the way you want to include your php_self value.
also
<input type="submit" value="LIKE" name="<?php echo $row["wordID"]; ?></form>
should be
<input type="submit" value="LIKE" name="'.$row['wordID'].'"></form>
but you cant the search for $_POST['wordID'], search for $_POST[$row['wordID']] in a for loop.

Answer 2

You're doing an echo inside an echo here :
echo '<td>
<form method="post" action="<?php echo $_SERVER["PHP_SELF"]?>
<input type="submit" value="LIKE" name="<?php echo $row["wordID"]; ?></form>
</td>';
<form method="post" action="<?php echo $_SERVER["PHP_SELF"]?>
should be :
<form method="post" action="'.$_SERVER["PHP_SELF"].'">

Answer 3

i would do this:
<td>
<form method='POST'>
<input type='hidden' name='LIKE' value='".$row['wordId']."'>
<input type='submit' value='Submit'>
</form>
</td>
Action will always default to : PHP_SELF so no point adding that, additionally adding the hidden field instead of the submit button is preferable to me as it's easier to read, plus adds an easy option incase you actually want to add more to the form (which is entirely possible)