小编Ham*_*bir的帖子

我有一个sql文件来过滤数据

-- Edit this file by adding your SQL below each question.
-------------------------------------------------------------------------------

-------------------------------------------------------------
-- The following queries are based on the 1994 census data.
-------------------------------------------------------------

.read 1994
-census-summary-1.sql

-- 4. what is the average age of people from China?
select avg(age)
from census
where native_country ='China';

-- 5. what is the average age of people from Taiwan?
select avg(age)
from census
where native_country ='Taiwan';

-- 6. which native countries have "land" in their name?
select distinct(native_country)
from census
where …