Question

我正在使用此查询来搜索标签相似性

SELECT sites_id
    FROM tags_to_sites
    WHERE tags_id IN (SELECT tags_id FROM tags_to_sites WHERE sites_id= ?)
    AND sites_id!= ?
    GROUP BY sites_id
    HAVING COUNT(*) = (  SELECT COUNT(*)  FROM  tags_to_sites
    WHERE tags_id IN (SELECT tags_id FROM tags_to_sites WHERE sites_id= ?)
      AND sites_id!= ?
    GROUP BY sites_id
    ORDER BY COUNT(*) DESC LIMIT 3)

但我收到错误

SQLSTATE [21000]：基数违规：1242子查询返回更多超过1行

有谁知道为什么？

Answer 1

正确的查询

SELECT sites_id
    FROM tags_to_sites
    WHERE tags_id IN (SELECT tags_id FROM tags_to_sites WHERE sites_id= ?)
    AND sites_id!= ?
    GROUP BY sites_id
    HAVING COUNT(*) = (  SELECT COUNT(*)  FROM  tags_to_sites
    WHERE tags_id IN (SELECT tags_id FROM tags_to_sites WHERE sites_id= ?)
      AND sites_id!= ?
    GROUP BY sites_id
    ORDER BY COUNT(*) DESC LIMIT 1)
LIMIT 3

MYSQL：基数违规：1242子查询返回超过1行？

1 个答案: