SQL返回多个计数语句

Question

我有一张桌子，里面有世界各地的滑雪胜地。该表还确定了他们所在的国家和“部门”（美国/欧洲/亚洲等）。我正在尝试确定每个部门的度假村数量。

示例数据：

resort_id, resort_name, country_id, sector_id
3376    Chréa           204  204
3377    Tikjda          204  204
3384    Beidahu         208  205
3481    Canyon Ski Area 225  206
3482    Castle Mountain 225  206
3483    Drumheller      225  206

我需要能够确定每个部门的度假村数量，即：

Sector       Resorts
--------------------
204          2
205          1
206          3

非常感谢任何帮助。

Answer 1

select sector_id,
       count(*)
from   resortTableName
group by sector_id

并解决您编辑过的问题：

select sector_id,
       count(distinct resort_name) as resortCount,
       count(distinct country_id) as countryCount
from   resortTableName
group by sector_id

Answer 2

您只需要count并按行业分组结果：

SELECT   sector_id, COUNT(*)
FROM     resorts
GROUP BY sector_id

Answer 3

这是一个简单的group By

Select count(*) As Resorts, sector_id as Sector 
from yourtablename 
group by sector_id