如何排除总票数小于1的帖子？

Question

这是我的问题：

SELECT count(1)
 FROM qanda question
 JOIN qanda answer ON question.Id = answer.related
WHERE answer.related IS NOT NULL
  AND answer.author_id = ?
  AND question.amount IS NULL
  AND answer.date_time >= UNIX_TIMESTAMP(now() - INTERVAL 1 YEAR) AND UNIX_TIMESTAMP(now() - INTERVAL 1 hour)
  AND answer.id NOT IN (
      SELECT post_id
      FROM votes
      WHERE table_code = 15
      GROUP BY post_id
      HAVING SUM(value) < 0 )

我的查询返回用户的答案数为零或总票数（总票数：0,1,2，......）。现在我需要排除0总票数的答案。

因此我取代：

... HAVING SUM(value) < 0

与

... HAVING SUM(value) < 1

但它没有按预期工作。我的意思是它仍然计算总票数为零的答案。怎么了？我该如何解决？

Answer 1

如果我理解正确，请使用in代替not in并反转您的having条件：

...
answer.id IN (
      SELECT post_id
      FROM votes
      WHERE table_code = 15 
      GROUP BY post_id
      HAVING SUM(value) > 0)

Answer 2

问题是您的内部查询没有选择否投票的帖子，因此不排除 。有几种方法可以解决这个问题，但最简单的方法是将排除的逻辑从反向转换为包含，即＆＃34; show已投票总数的帖子＆gt; 1＆＃34;：

SELECT count(1)
 FROM qanda question
 JOIN qanda answer ON question.Id = answer.related
WHERE answer.related IS NOT NULL
  AND answer.author_id = ?
  AND question.amount IS NULL
  AND answer.date_time BETWEEN UNIX_TIMESTAMP(now() - INTERVAL 1 YEAR) AND UNIX_TIMESTAMP(now() - INTERVAL 1 hour)
  AND answer.id IN ( -- remove "NOT"
      SELECT post_id
      FROM votes
      WHERE table_code = 15
      GROUP BY post_id
      HAVING SUM(value) > 0 ) -- change to > 0

作为加入：

SELECT count(*) FROM (
  SELECT answer.id
  FROM qanda question
  JOIN qanda answer ON question.Id = answer.related
  JOIN votes ON votes.post_id = answer.id 
      AND votes.table_code = 15
   WHERE answer.related IS NOT NULL
   AND answer.author_id = ?
   AND question.free IS NULL
   AND answer.date_time BETWEEN UNIX_TIMESTAMP(now() - INTERVAL 1 YEAR)
     AND UNIX_TIMESTAMP(now() - INTERVAL 1 hour)
   AND answer.timestamp > subdate(now(), 365)
   GROUP BY answer.id
  HAVING SUM(votes.value) > 1) x