MySQL:根据另一个表中的多个值从一个表中选择多个值

Question

我想返回关于每个区域的所有报告，属于一个宏观区域...

我想以某种方式

SELECT DISTINCT report FROM reports WHERE region = 
(SELECT distinct region from macroregions where macroregion = 'Africa') 

宏观区域有撒哈拉、西非、热带非洲……等

尽管这是不可能的，因为子查询会返回多个结果。

Answer 1

SELECT DISTINCT report FROM reports WHERE 
region IN 
(SELECT distinct region from macroregions where macroregion = 'Africa') 

也许你错过了 IN 运算符