public void update(Book book){
		String update = "update book set name = ?,author =?, bookman =?,price=?," +
				"categoryId=?,introduction=?,onSaleDate=?,onSaleNum =?,remainNum=? where id = "+ book.getId();
		
		DBManager dbm = null;
		Connection conn= null;
		PreparedStatement pstmt = null;
		
		try{
			dbm = new DBManager();
			conn= dbm.getConnection();
			pstmt = conn.prepareStatement(update);
			
			pstmt.setString(1,book.getName());
			pstmt.setString(2,book.getAuthor());
			pstmt.setString(3,book.getBookman());
			pstmt.setFloat(4,book.getPrice());
			pstmt.setInt(5, book.getCategoryId());
			pstmt.setString(6,book.getIntroduction());
			pstmt.setDate(7,book.getOnSaleDate());
			pstmt.setInt(8, book.getOnSaleNum());
			pstmt.setInt(9,book.getRemainNum());
			
			pstmt.executeUpdate();
			
		}catch(Exception e){
			e.printStackTrace();
		}finally{
			dbm.closeAll(null, pstmt, conn);
		}
	}