Oracle查询我怎样才能在Oracle显示的计数()柱记录的最大/最小
select
courses.name,
count(gardener)
from
attendances
join courses using (course)
group by
courses.name
order by
count(gardener) asc
输出
╔═══════════╦═════════════════╗
║ NAME ║ COUNT(GARDENER) ║
╠═══════════╬═════════════════╣
║ Harvesting║ 3 ║
║ Planting ║ 3 ║
║ Gardening ║ 4 ║
╚═══════════╩═════════════════╝
如何可以只显示的最小/最大,甚至平均计数。例如。最小
// I just want to display the courses with minimum count
╔═══════════╦═════════════════╗
║ NAME ║ COUNT(GARDENER) ║
╠═══════════╬═════════════════╣
║ Harvesting║ 3 ║
║ Planting ║ 3 ║
╚═══════════╩═════════════════╝
我试图
select
max(cnt), -- min(cnt) and avg(cnt) doesnt seem to work
name
from
(
select
courses.name,
count(gardener) as cnt
from
attendances
join courses using (course)
group by
courses.name
order by
count(gardener) asc
)
group by
name
我得到无效的标识符 “CNT”。我尝试使用max(cnt)它也给了我相同的标识符错误,任何人都可以纠正我的语法,并建议我做错了请或者建议一种不同的方式来做到这一点?
编辑:我删除了语音标记,但仍然显示所有记录,而不仅仅是最大值count()记录,因为我需要。
非常感谢你,会考虑一下。 – 2014-12-07 01:53:16