帮助子查询！返回多于1行 [英] help with subquery! returns more than 1 row

问题描述

我不了解返回多行的问题:

i dont understand the problem with returning multiple rows:

这是我的桌子BBC:

name    region  area    population  gdp
Afghanistan South Asia  652225  26000000    
Albania Europe  28728   3200000 6656000000
Algeria Middle East 2400000 32900000    75012000000
Andorra Europe  468 64000   
Angola  Africa  1250000 14500000    14935000000
etc.............................

问题:

列出国家名称和地区 在包含印度"的地区， 伊朗".

List the name and region of countries in the regions containing 'India', 'Iran'.

这是我的声明

select name from bbc where region = (select region from bbc where name='India' or name='Iran')

它返回:

sql: errorSubquery returns more than 1 row

我的陈述有什么问题?答案应为选择语句中选择语句的形式

whats wrong with my statement? the answer should be in the form of a select statement within a select statement

谢谢！

推荐答案

这是因为您试图将region与值表进行比较.而是尝试使用in:

This is because you are trying to compare region to a table of values. Instead, try using in:

select name 
from bbc 
where region in 
    (select region from bbc where name='India' or name='Iran')

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