我在这里有一个疑问:对于美国的每个国家,请给出最高的山峰及其高度;按高度排序。和表格:
encompasses : country,continent
geo_mountain: mountain,country
mountain:name,height
我是这样写的:
select co.country,mo.name, max(mo.height) as mheight
from mountain mo,encompasses co
join geo_mountain gmo
on mo.name=gmo.mountain
where gmo.country=any (select country from encompasses where continen='America')
GROUP BY co.country
order by mheight;
但我在 oracle 11g 中收到此错误:
Error at Command Line:203 Column:4(second like)
SQL Error: ORA-00904: "MO"."NAME": invalid identifier