sql-server - SQL统计组数

Question

我有一张 table ，上面有托盘、元素、元素数量:

pallet | item | qty
-------------------
  1        1     2
  1        2     4
  2        3     2
  2        5     3
  3        4     4

我需要找到计数(托盘)、计数(项目)、总和(数量)

count(pallets) | count(items) | sum(qty)
----------------------------------------
      3                5           15

我可以使用

获取总和(数量)和计数(项目)

select count(0) as totalItems, sum(qty) as total from table

有没有办法无需子查询即可获取托盘数量？

Answer 1

是的，使用DISTINCT

select count(distinct pallet) as pallets,
       sum(qty) as total, 
       count(*) as totalItems 
from your_table