Böyle deneyin:
<?php
$exists = $wpdb->get_var("SELECT COUNT(*) FROM wp_posts WHERE post_title = '$baslik'");
$kontrolyap=mysql_num_rows($exists);
if($kontrolyap==0){
?>
<button type="button" onClick="gonder<?php echo $i; ?>();" >Ekle</button>
<?php }else{?>
<b> zaten eklenmis ! </b>
<?php } ?> Warning: mysql_num_rows() expects parameter 1 to be resource, string given in
$kontrolyap=mysql_num_rows($exists);