有没有办法加入下面的SELECT语句？

Question

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';

Answer 1

您已经将位置作为国家/地区名称。所以不需要 select 列 people_fully_vaccinated

如果您想按特定国家/地区进行过滤，请使用以下内容：

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

如果你想得到全部，那么使用下面这个：

SELECT date,location FROM vaccinations;

Answer 2

如果您不关心每个国家/地区的数据是否在不同的行中，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;

有没有办法加入下面的SELECT语句？

Is there a way to join the following SELECT statements?

sql

sqlite

select