有没有办法加入以下 SELECT 语句？答案

【问题标题】：Is there a way to join the following SELECT statements?有没有办法加入以下 SELECT 语句？
【发布时间】：2021-12-15 10:00:36
【问题描述】：

SELECT 
    date, 
    people_fully_vaccinated AS 'Australia'
FROM vaccinations 
WHERE location = 'Australia';
SELECT 
    date, 
    people_fully_vaccinated AS 'United States'
FROM vaccinations 
WHERE location = 'United States';
SELECT 
    date, 
    people_fully_vaccinated AS 'France'
FROM vaccinations 
WHERE location = 'France';
SELECT 
    date, 
    people_fully_vaccinated AS 'Israel'
FROM vaccinations 
WHERE location = 'Israel';

【问题讨论】：

标签： sql sqlite select

【解决方案1】：

您已经将位置作为国家/地区名称。所以无需选择列 people_fully_vaccinated

如果您想按特定国家/地区过滤，请在下方使用：

SELECT date
    ,location
FROM vaccinations
WHERE location = 'Australia'
    OR location = 'United States'
    OR location = 'France'
    OR location = 'Israel'

如果您想全部获取，请在下面使用：

SELECT date,location FROM vaccinations;

【讨论】：

【解决方案2】：

如果您不关心每个国家/地区的数字位于不同的行中，您可以使用：

select    date,
          location,
          people_fully_vaccinated
from      vaccinations
where     location in ('Australia','United States','France','Israel');

如果您希望每个国家/地区的数字在每个日期出现在同一行，您可以使用：

select    date,
          sum(case when location = 'Australia' then people_fully_vaccinated else 0 end)     as "Australia",
          sum(case when location = 'United States' then people_fully_vaccinated else 0 end) as "United States",
          sum(case when location = 'France' then people_fully_vaccinated else 0 end)        as "France",
          sum(case when location = 'Israel' then people_fully_vaccinated else 0 end)        as "Israel"
where     location in ('Australia','United States','France','Israel')
group by  date;

【讨论】：

感谢您的回答。第二个是我需要的