oracle中to_date()用法

select sum(t.data) outdata,sum(t.indata) indata,day from bandwidth_dailytable_channel t where t.channelid='3001' and t.day<=to_date('2009-07-02-23:59','yyyy-mm-dd-hh24:mi') and t.day>=to_date('2009-07-01-00:00','yyyy-mm-dd-hh24:mi')  group by t.day order by t.day

 

 

把这句贴出来相信都能看懂了。

 

补充一下：

 

sum()求和后，通过group by 来分组把哪些数据用来求和