需要帮助创建具有两个不同宠物总和的视图答案

【问题标题】：Need help creating a view with two different pet sums需要帮助创建具有两个不同宠物总和的视图
【发布时间】：2019-04-19 01:35:18
【问题描述】：

我正在尝试创建一个视图，该视图创建一个表格，其中给出了狗的总和和猫的总和。这是我目前拥有的。但我不确定如何进入视图格式。

select count(PetType) as [Amount of Dogs]
from Pets
where pettype = 'dog'

select count(PetType) as [Amount of Cats]
from Pets
where PetType = 'cat'

感谢您的帮助。

【问题讨论】：

标签： tsql join count sum

【解决方案1】：

CREATE VIEW v AS
SELECT * FROM
(select count(PetType) as [Amount of Dogs] from Pets where pettype = 'dog') d
CROSS JOIN
(select count(PetType) as [Amount of Cats] from Pets where PetType = 'cat') c

【讨论】：

【解决方案2】：

只需使用条件聚合：

select sum(case when PetType = 'dog' then 1 else 0 end) as num_dogs,
       sum(case when PetType = 'cat' then 1 else 0 end) as num_cats
from Pets;

【讨论】：