onclicking button only the last post changes - php

Question

no matter whichever btn i click only the last post's count changes...how do i get the corresponding count to change
<?php
// Query the custom post type to display
$args = array('post_type' => 'books');
$query = new WP_Query( $args );
while ( $query->have_posts() ) :
$query->the_post();
if ( has_post_thumbnail() ):
$postid = get_the_ID();
$oldcount=get_field('count');
$newcount=$oldcount+1;
?>
<form action="#" method="post">
<div><?php the_post_thumbnail('thumbnail'); ?><input id="<?php echo $postid;?>" type="submit" name="submit" value="Vote" /><?php echo " ".$oldcount;?></div>
</form>
<?php endif; endwhile; ?>
<?php
if (isset($_POST['submit'])) {
$ID = $_GET['id'];
echo $ID;
echo " button clicked";
update_field('field_55014a',$newcount,$ID);
}
?>

Answer 1

You are submitting the form via POST but trying using $_GET['id'] this does not correspond to <input id="<?php echo $postid;?>">
Change the form so that it submits the post id:
<?php
// THIS PORTION OF THE CODE MUST COME FIRST!!!!!
if (isset($_POST['submit'])) {
$id = $_POST['id'];
$newcount = // query your database, get the vote count then add one.
update_field('field_55014a',$newcount,$id);
header('Location: '. $_SERVER['PHP_SELF']);
exit();
}
$args = array('post_type' => 'books');
$query = new WP_Query( $args );
while ( $query->have_posts() ) {
$query->the_post();
if ( has_post_thumbnail() ) {
$postid = get_the_ID();
$votecout =get_field('count');
?>
<form action="" method="POST">
<div>
<?php the_post_thumbnail('thumbnail'); ?>
<input type="hidden" value="<?php echo $postid; ?>" name="id" />
<input type="submit" name="submit" value="Vote" />
<?php echo $oldcount; ?>
</div>
</form>
<?php
} // close if
} // close while