functions

Én valahogy így csinálnám meg. Nem mondom biztosra, hogy működik, mert nem teszteltem le.
<?php

if(isset($_GET['p'])) $edit_slug = $_GET['p'];

if(!empty($edit_slug)) $this->get_post($edit_slug);
else die ("Sorry, this functions is not working!");

function get_post($edit_slug)
{
  global $con;

  $sql  = "SELECT * FROM posts WHERE post_slug = ?";

  $stmt = mysqli_stmt_init($con);

  $stmt = $this->query();

  mysqli_stmt_bind_param($stmt, "s", $edit_slug);

  $result = mysqli_stmt_get_result($stmt);

  while($row = mysqli_fetch_assoc($result))
    {
      $post_id            = $row['post_id'];
      $post_category_id   = $row['post_category_id'];
      $post_status_id     = $row['post_status_id'];
      $post_user_id       = $row['post_user_id'];
      $post_title         = $row['post_title'];
      $post_date          = $row['post_date'];
      $post_image         = $row['post_image'];
      $post_content       = $row['post_content'];
      $post_tags          = $row['post_tags'];
      $post_comment_count = $row['post_comment_count'];
      $post_slug          = $row['post_slug'];
    }

    mysqli_stmt_close($stmt);
} // function

function query($con, $sql)
{
    $stmt = mysqli_stmt_init($con);

    if(!mysqli_stmt_prepare($stmt, $sql)) { die('QUERY FAILED: ' . mysqli_error($con)); }

    return $stmt;
}