@Override
	public boolean delete(Object item) {
		conn = new SQLconnect().getConnection();
		String sqlcommand = "UPDATE `Timeline_Database`.`Eventnodes` SET `display`='false' WHERE `id`='%s';";
		if(item instanceof Eventnode)
		{
			Eventnode newitem = new Eventnode();
			newitem = (Eventnode)item;
			try {  
					String sql = String.format(sqlcommand,newitem.getId());
					Statement st = (Statement) conn.createStatement();    // 创建用于执行静态sql语句的Statement对象  
					System.out.println(sql);
					int count = st.executeUpdate(sql);  // 执行插入操作的sql语句，并返回插入数据的个数  
					System.out.println("delete " + count + " entries"); //输出插入操作的处理结果
					conn.close();
					return true;
			}catch (SQLException e) {
				System.out.println("删除数据失败 " + e.getMessage());
				return false;
			}
		}
		return false;
	}