我试图返回两个子查询的乘积，并认为我可以通过给每个子查询加上别名来让生活更轻松，然后将两个别名相除以获得我想要的数字，如下所示：
select distinct
(select SUM(pest.AREA_HA) from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest
where ORG_UNIT_NO IN (1904, 1830,1831, 1902)) as Ha_IN_RKB,
(select SUM(pest.AREA_HA) from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest) as Ha_total,
ROUND( (Ha_IN_RKB / Ha_total) ,3)
from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest
但这会导致 00904. 00000 - “%s: invalid identifier” 错误（Oracle 不喜欢Ha_IN_RKBor Ha_total）。
如下重写查询是可行的，但相当庞大：
select distinct
(select SUM(pest.AREA_HA) from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest
where ORG_UNIT_NO IN (1904, 1830,1831, 1902)) Ha_IN_RKB,
(select SUM(pest.AREA_HA) from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest) Ha_total,
ROUND( ((select SUM(pest.AREA_HA) from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest
where ORG_UNIT_NO IN (1904, 1830,1831, 1902)) /
(select SUM(pest.AREA_HA) from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest)) ,3) as RKB_pct
from WHSE_FOREST_VEGETATION.PEST_INFESTATION_POLY pest
有人知道为什么我不能做这个ROUND( (Ha_IN_RKB / Ha_total) ,3)工作吗？