复杂报表的高效查询

High Speed Query of Complicated Report

复杂报表由于要对系统中大量数据进行查询、统计、分析和汇总,需要占用较多的时间,如果没有进行优化,那响应的时间将是无法接受的。而减少访问数据表的次数,是提高报表产生效率的重要方法。结合前台开发工具和后台数据库的特性,恰当设置分组,利用数组保存报表设置参数和中间结果,巧妙利用数据库的特色函数,设计出高效查询的程序段,以达到访问数据表一次就完成统计任务的目的。

Because of the queries, statistics, analysis and summaries of the large data, to generate complicated report takes up much time. The response time is not able to be accepted without optimizing. Reducing times of accessing to data table, it is an important way of improving the efficiency of generating report. With the characteristics of the foreground development tool and the background database, setting the groups properly, saving the report setting parameters and the middle results, and using the particular functions of database, the program codes for high speed query can be designed to perform statistical task by access to data table once.