Oracle 多个查询语句结果合并

有三个不同的查询语句
1：

select year_mon,sum(gasmon) 
from a 
where id='HBsRf0t6UI' 
and class=11 
group by year_mon 

2：

select year_mon,sum(wellgasmon) 
from b 
where id='HBsRf0t6UI' 
and class=11 
group by year_mon

3：

select year_mon,sum(gasprodmon) 
from c 
where id='HBsRf0t6UI' 
and class=11 
group by year_mon 

希望能显示出下面的效果：

year_mon  sum(gasmon)  sum(wellgasmon)    sum(gasprodmon) 
200702     122                  222                       123 
200703     333                  234                        342 
200704     0                      2334                      0 
200705     324                  2342                      234 

这样的效果也行。
问题解决

SELECT   year_mon, SUM (gasmon), SUM (wellgasmon), SUM (gasprodmon)
    FROM (SELECT   year_mon, SUM (gasmon) gasmon, 0 wellgasmon, 0 gasprodmon
              FROM a
             WHERE ID = 'HBsRf0t6UI' AND CLASS = 11
          GROUP BY year_mon
          UNION ALL
          SELECT   year_mon, 0, SUM (wellgasmon), 0
              FROM b
             WHERE ID = 'HBsRf0t6UI' AND CLASS = 11
          GROUP BY year_mon
          UNION ALL
          SELECT   year_mon, 0, 0, SUM (gasprodmon)
              FROM c
             WHERE ID = 'HBsRf0t6UI' AND CLASS = 11
          GROUP BY year_mon)
GROUP BY year_mon

评论

1 楼 eclipsejob 2014-11-16  

这种写法，如果数据量大的情况下性能是不是就没法看了呢