Im working on wordpress database directly. im trying to get category detail of a post by id, so i query for post, and query for the category where multiple category of same post. I'm new for this PDO method. can any one help me for this:

//Get Categories
 public function categories($post_id) {
 $query = "SELECT term_taxonomy_id FROM wp_term_relationships WHERE object_id = ?";
 $stmt = $this->conn->prepare($query);
 $stmt->execute([$post_id]);
 $term = array();
 while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
 extract($row);
 $term[] = $row['term_taxonomy_id'];
 }

 $query = "SELECT * FROM wp_terms WHERE term_id IN (";
 $comma = '';

 for($i=0; $i<count($term); $i++){
   $query .= $comma.':p'.$i;      // :p0, :p1,
   $comma = ',';
 }
 $query .= ')';

 $stmt = $this->conn->prepare($query);

 for($i=0; $i<count($term); $i++){
 if(isset($term[$i])) {
 $stmt->bindValue(':p'.$i, $term[$i], PDO::PARAM_INT);
 }
 }

 $stmt->execute();

 $category = array();
 while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
 extract($row);
 $category[] = array(
 'id'=> $row['term_id'],
 'slug'=> $row['slug'],
 'title'=> $row['name']
 );
 }

 return $category;
 }

The error im getting is

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064