public function fetchAllColumn() {
		return $this->db->fetchRows($this->toSql(), $this->getBindings(), PDO::FETCH_COLUMN);
	}
public function fetchAllColumn() {
		return $this->db->fetchRows($this->toSql(), $this->getBindings(), PDO::FETCH_COLUMN);
	}
public function fetchAllColumn ( ) { return $ this -> db -> fetchRows ( $ this -> toSql ( ) , $ this -> getBindings ( ) , PDO :: FETCH_COLUMN ) ; }
Fetch all values of a single column from the result set into an array.

@return array
Fetch all values of a single column from the result set into an array .