我有5个表是设备日志,表是相同的,只是按月划分,您需要将它们粘合到一个表中并使用DEVICES_ACTIVE将其连接到主键。
1. Table DEVICES_ACTIVE
DEVICE_ID NUMBER(38,0) PK
2. Table DJ_05_2014
DEVICE_ID NUMBER(38,0) PK
START TIMESTAMP
STOP TIMESTAMP
3. Table DJ_06_2014
DEVICE_ID NUMBER(38,0) PK
START TIMESTAMP
STOP TIMESTAMP
4. Table DJ_07_2014
DEVICE_ID NUMBER(38,0) PK
START TIMESTAMP
STOP TIMESTAMP
......................
答案 0 :(得分:1)
select ...
from devices_active
join (select ... from dj_07_2014 union all
select ... from dj_06_2014 union all
select ... from dj_05_2014
) using(device_id);