血库系统提供了常用的查询与统计功能，通过查询与统计可以查询出各种所需的信息以及日常报表，在此不再一一介绍。-Blood bank system provides a common query and statistical functions, search and statistic can be queried by various kinds of necessary information and daily reports, in this descr iption is no lon

DML的数据查询指对数据库中的数据查询、统计、分组、排序等操作。查询语句可以分为简单查询、连接查询、嵌套查询和组合查询。-The DML data query refers to the data in the query, statistic, grouping, sorting, and so on. Query can be divided into simple query, join queries, nested query and combination query.

一种基于窗口函数的指定时间段内累积量统计算法(A statistic algorithm based on window function in specified time interval)