WordPress保存到数据库（ajax）

Question

所以我有这个代码（PHP和jQuery），它应该将数据保存到WordPress数据库并检测数据库中是否已存在该帖子。如果帖子存在，则回显“已经保存”。

问题是，它可以保存一些物品，而不会保存其他物品。我不知道还有什么可以调试这个问题。

public static function wpnp_save_news(){
        global $wpdb;
        $table_name = $wpdb->prefix.'wpnp';

        if (is_user_logged_in()) {
          if (isset($_POST['delete'])) {
            $id = $_POST['id'];
            $wpdb->delete( $table_name, array( 'id' => $id ) );
            echo "Article deleted";
          }elseif (isset($_POST['savefav'])) {
            $user = $_POST['user_id'];
            $title = mysql_real_escape_string($_POST['title']);
            $sql = "SELECT count(*)  FROM $table_name  WHERE user=$user and title='".$title."'";
            $count = $wpdb->get_var($sql);


          if($count <= 0 ){
              $wpdb->insert(
                $table_name,
                array(
                  'user' => $_POST['user_id'],
                  'title' => $_POST['title'],
                  'summary' => $_POST['summary'],
                  'url' => $_POST['post_url'],
                  'img' => $_POST['img_url'],
                  'author' => $_POST['author'],
                  'source' => $_POST[ 'source']
                )
                );
                echo "Article saved";
            }else{
                echo "Article already saved";
            }
          }else{
            echo "Please login to save articles";
          }
        }
      wp_die();
      } 
-----------------------------------------
$('.wpnp-delete').on('click',(e)=>{
        e.preventDefault();
        const url = wpnpObj.au;
        const delete_data = {
          action: wpnpObj.ff,
          'delete': true,
          'id': e.currentTarget.dataset.id
        };
        const success = data =>{
          alert(data)
          window.location.reload()
        };
        const err = data =>{
          console.log(data);
        }
      $.post(url,delete_data,success).fail(err);
})