How many countries had a percent forestation higher than the United States in 2016?
求解2016年 有多少个国家 的森林覆盖率大于美国。
SELECT COUNT()
FROM forest_area f
JOIN land_area l
ON f.country_code = l.country_code
AND f.year = l.year
WHERE f.forest_area_sqkm/(l.total_area_sq_mi2.59) >
(SELECT f.forest_area_sqkm/(l.total_area_sq_mi*2.59)
FROM forest_area f
JOIN land_area l
ON f.country_code = l.country_code
AND f.year = l.year
WHERE f.country_code = USA
) AND YEAR = 2016
请问我的结构有问题吗? 我用AND 连接所有森林覆盖率大于美国的国家AND年份=2016
这会达到我选择的效果吗?还是用HAVING YEAR = 2016?