1 怎样让时间这个字段在每次生成记录(一行)时,自动填写当时的sysdate.
2 表A (CITY_ID,user_id,operation_up,operation_down) 一个用户只能有一种操作(UP,或者,DOWN),想要统计每个CITY_ID有多少用户ID,每个CITY_ID有多少UP操作,有多少DOWN操作.
生成一个新表B(CITY_ID,USER_ID_SUM,UP_SUM,DOWN_SUM)
2 表A (CITY_ID,user_id,operation_up,operation_down) 一个用户只能有一种操作(UP,或者,DOWN),想要统计每个CITY_ID有多少用户ID,每个CITY_ID有多少UP操作,有多少DOWN操作.
生成一个新表B(CITY_ID,USER_ID_SUM,UP_SUM,DOWN_SUM)
2.
create table b as
select CITY_ID,user_id,sum(operation_up) UP_SUM,sum(operation_down) DOWN_SUM
from a group by city_id,user_id
alter table tablename datafield date default sysdate;