摘要：
一、聚集函数的使用：avg(...), sum(...), min(...), max(...)count(*)count(...), count(distinct ...), count(all...)public DailyStatistics getPreviousDayStatistics(Integer dateNumber) { String hql = "from DailyStatistics bean where bean.dateNumber=" + "(select max(ds.dateNumber) from Dai... 阅读全文