function get_posts_by_category($categories_id){
global $connect;
$categories_id = mysqli_real_escape_string($connect,$categories_id);
$category_sql = 'SELECT * FROM articles WHERE categories_id = "'. $categories_id .'"';
$category_result = mysqli_query($connect,$category_sql);
$category_post = mysqli_fetch_assoc($category_result);
return $category_post;
}