0001以下、5ちゃんねるからVIPがお送りします
2023/06/28(水) 22:43:02.073ID:Equ6WtIt0サブクエリーでa.continent =b.continentになるけどその意味は?
SELECT
name,continent,population
FROM
world A
WHERE
25000000>=ALL(SELECT population
FROM world B
WHERE B.continent=A.continent);
https://sqlzoo.net/wiki/SELECT_within_SELECT_Tutorial/ja