摘要： Oracle Aggregate Functions用过很多，官网的说明如下：Aggregate Functionshttp://docs.oracle.com/cd/E11882_01/server.112/e26088/functions003.htm#SQLRF20035 Aggregatefunctions return a single result row based on groups of rows, rather than onsingle rows. Aggregate functions can appear in select lists and inORDERBYan 阅读全文