public boolean isUpdate(String sql, String[] params) {
		boolean b = true;
		try {
			Class.forName(driver);
			System.out.println("ɹ");
			connection = DriverManager.getConnection(url,username,password);	 //ݿ
			System.out.println("ݿɹ!");
			ps = connection.prepareStatement(sql);			//ȡPreparedStatement
			
			//ѭϣSQLе"?"
			for (int i = 0; i < params.length; i++) {
				ps.setString(i+1, params[i]);
			}
			//ִвȡӰ
			int i = ps.executeUpdate();
			if (i != 1) {
				b = false;
			} else {
				b = true;
			}
			rs = ps.executeQuery();			
		} catch (SQLException e) {
			// TODO: handle exception
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO: handle exception
			e.printStackTrace();
		} finally {
			this.close();
		}
		return b;		//ResultSet
	}