mysql - 如何对单个列执行 AND 运算？

Question

我有一个包含两列的表格；

CREATE TABLE IF NOT EXISTS `QUESTION_CATEGORY_RELATION` (
  `question_id` int(16) NOT NULL,
  `category_id` int(16) NOT NULL,
  KEY `category_id` (`category_id`),
  KEY `question_id` (`question_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `QUESTION_CATEGORY_RELATION` (`question_id`, `category_id`) VALUES
(1, 2),
(1, 3),
(2, 1),
(2, 2);

我想创建一个查询来搜索 content_id 为 2 和 content_id 为 3 的 question_id

例如:

SELECT *  
FROM `QUESTION_CONTENTS_REL` 
WHERE `content_id` = 2 AND `content_id` = 3

Answer 1

SELECT question_id
FROM QUESTION_CONTENTS_REL
WHERE content_id in (2, 3)
group by question_id
having count(distinct content_id) = 2