Question

怎么将两个结果集加到一起【sql】

怎么将两个结果集加到一起【sql】
select a.sensorid sensorid ,'2008-10-19 '||to_char(t.time1,'hh24') cptime from usedseninfotab a,time_interval t where
a.sensorid=318

和
select a.sensorid sensorid ,'2008-10-20 '||to_char(t.time1,'hh24') cptime from usedseninfotab a,time_interval t where
a.sensorid=318

把后面一个结果集并在前面的后面，要怎么做

Answer 1

union all忽略向同值

select a.sensorid sensorid ,'2008-10-19 '||to_char(t.time1,'hh24') cptime from usedseninfotab a,time_interval t where
a.sensorid=318 union all
select a.sensorid sensorid ,'2008-10-20 '||to_char(t.time1,'hh24') cptime from usedseninfotab a,time_interval t where
a.sensorid=318

Answer 2

要将sql里的结果集链接起来必须这两个结果集里面的字段一样
在这两个sql语句中间加union来联接

Answer 3

可以分别把连个结果集创建成视图。然后在两个试图进行检索就比较简单了。
create view temp1 as (select ....)
create view temp2 as (select ....)
select a.*,b.* from temp1 a,temp2 where a.主键=b.主键