从过去两个小时内从Oracle数据库获取数据？

Question

我想从两个小时前到currentime_stamp之间的Oracle数据库中获取数据。 我怎样才能做到这一点？

select count(*) as "trn<5",ROUND(avg (RESPONSE_TIME),2) as avr,ssn 
    from db_activity a 
    where a.REQ_TIMESTAMP BETWEEN current_timestamp -2 AND current_timestamp
 group by ssn

Answer 1

使用TIMESTAMP ，最好使用INTERVAL ：

select count(*) as "trn<5",ROUND(avg (RESPONSE_TIME),2) as avr,ssn 
    from db_activity a 
    where a.REQ_TIMESTAMP BETWEEN current_timestamp - INTERVAL '2' HOUR AND current_timestamp
group by ssn

Answer 2

...where a.REQ_TIMESTAMP  >= (SYSDATE-1/12)