基于客户机/服务器模式的数据共享访问

Sharing data on client/server model

针对在客户机／服务器模式下进行软件开发工作中常见的问题，讨论了当群组成员访问共享数据时出现的丢失更新、访问未提交的数据等错误情况，给出了加减法、加锁法、时标法等３种把在群组活动中产生的共享信息补充到公共数据库的方法，支持系统正确地完成信息的输入、存贮、检索和运算操作。

In order to solve the questions based on client/server model while software development running, the condition is discussed when multi--user in work group visited the same date at the same time, and the method is given for putting the sharing information into database. According to CSCW system, when one user updates the sharing information, other users should be informed at once. Otherwise, the data will be mass, for example, the new data is lost, or the wrong data is visited, etc. To solve these questions, there are three methods:addition-subtraction instruction method, lock method, time stamp method.