Question

我是这里的新用户，我认为这太棒了！我需要一些帮助：

我这样做，但不要像我想的那样工作！（count（countOfCat）不好！）

select count(countOfCat) as "Cat", count(countOfDog) as "dog", count(countOfHorse) as "horse", 0 as "duck", 0 as "Mouse"
from animal
where Birthdate in
        (...
         -- i think not important
         ...
        )
        and ( species= 'cat' or species= 'dog' or species= 'horse')
group by species

我想要像这样收到

Cat     Dog     Horse   Duck   mouse
------- ------- ------- ------  -------
1234    2345    3456     0      0

...

我需要所有的计数都在同一行我不能利用这个

noGood- Cat   Dog     Horse   Duck    mouse
noGood- ----- ------ -------- ------- -------
noGood- 1234  0       0       0         0
noGood- 0     2345    0       0         0
noGood- 0     0       3456    0         0

谢谢你的时间！
哒！

Answer 1

select sum(case when species = 'cat' then 1 else 0 end) as "Cat", 
       sum(case when species = 'dog' then 1 else 0 end) as "Dog", 
       sum(case when species = 'horse' then 1 else 0 end) as "Horse", 
       0 as "duck", 
       0 as "Mouse"
from animal
where species in ('cat', 'dog', 'horse')

Answer 2

我也很惊讶你是新来的。：d

select
  (select count(*) from animal a where a.species = 'cat') as Cat,
  (select count(*) from animal a where a.species = 'horse') as Horse,
  (select count(*) from animal a where a.species = 'duck') as Duck
from
  dual

注意：dual是一个始终只有一行的系统表。这样的技巧很方便。

Answer 3

很简单。您需要做的就是删除group by子句：D

select count(countOfCat) as "Cat", count(countOfDog) as "dog", count(countOfHorse) as "horse", 0 as "duck", 0 as "Mouse"
from animal
where Birthdate in
        (...
         -- i think not important
         ...
        )
        and ( species= 'cat' or species= 'dog' or species= 'horse')

Oracle - count（）在同一行

3 个答案: