public void update(BookCategory bc){
		String update = "update bookcategory set name = ?  where id = "+ bc.getId()+";";
		DBManager dbm = null;
		Connection conn = null;
		PreparedStatement pstmt = null;
		
		try{
			dbm = new DBManager();
			conn = dbm.getConnection();
			pstmt = conn.prepareStatement(update);
			pstmt.setString(1,bc.getName());
			pstmt.executeUpdate();
		}catch(Exception e){
			e.printStackTrace();
		}finally{
			dbm.closeAll(null, pstmt, conn);
		}
	}