Sql 导致干扰的已联接表

我有一个很大但有点简单的SQL查询。基本上，我的网站上的用户在不同类型的活动中建立了声誉，例如写评论、留下评论和向数据库添加条目。在大多数情况下，这些点存储在信誉良好的行动表中，我通过左键反复加入信誉良好的行动表来检索它们。这感觉很草率，但基本上是有效的

我遇到的问题是其中两个声誉“reviewer”和“community”。与其他的不同，它们不存储在声誉良好的\u actions表中。取而代之的是，它们的值是从投票表中派生出来的，我首先通过左键连接comments表来访问投票表。出于某种原因，加入评论表会导致我的所有其他声誉成倍增长。在一次试验中，“档案管理员”的名声本来应该是25岁，但当我加入评论时，它膨胀到10050岁

我是SQL的新手，我已经尝试了我所知道的（即，将GROUPBY子句应用于users.id），但我还没有任何运气。如能提供一些指导，将不胜感激

SELECT users.*,
  SUM(COALESCE(reviewers.value, 0)) as reviewer,
  SUM(COALESCE(communities.value,0)) as community,
  SUM(COALESCE(developers.value,0)) as developer,
  SUM(COALESCE(moderators.value,0)) as moderator,
  SUM(COALESCE(marketers.value,0)) as marketer,
  SUM(COALESCE(archivists.value,0)) as archivist,
  SUM(COALESCE(karmas.value,0)) as karma
FROM `users`
LEFT JOIN comments AS impressions
  ON impressions.user_id = users.id
  AND impressions.type = 'impression'
LEFT JOIN comments AS replies
  ON replies.user_id = users.id
  AND replies.type = 'reply'
LEFT JOIN votes AS reviewers
  ON reviewers.voteable_type = 'impression'
  AND reviewers.voteable_id = impressions.id
LEFT JOIN votes AS communities
  ON communities.voteable_type = 'reply'
  AND communities.voteable_id = replies.id
LEFT JOIN reputable_actions AS developers
  ON developers.reputation_type = 'developer'
  AND developers.user_id = users.id
LEFT JOIN reputable_actions AS moderators
  ON moderators.reputation_type = 'moderator'
  AND moderators.user_id = users.id
LEFT JOIN reputable_actions AS marketers
  ON marketers.reputation_type = 'marketer'
  AND marketers.user_id = users.id
LEFT JOIN reputable_actions AS archivists
  ON archivists.reputation_type = 'archivist'
  AND archivists.user_id = users.id
LEFT JOIN reputable_actions AS karmas
  ON karmas.reputation_type = 'karma'
  AND karmas.user_id = users.id
GROUP BY users.id

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基本上，您需要进行两次单独的分组，并将结果合并。有一个技巧可以避免多次加入，如果您有许多其他可呕吐类型或声誉类型，可能不会更快

Select
  u.*,
  Coalesce(r.developer, 0) as developer,
  Coalesce(r.moderator, 0) as moderator,
  Coalesce(r.marketer, 0) as marketer,
  Coalesce(r.archivist, 0) as archivist,
  Coalesce(r.karma, 0) as karma,
  Coalesce(v.impressions, 0) as impressions,
  Coalesce(v.replies, 0) as replies
From
  users u
    Left Outer Join (
    Select
      user_id,
      Sum(Case When reputation_type = 'developer' Then value Else 0 End) as developer,
      Sum(Case When reputation_type = 'moderator' Then value Else 0 End) as moderator,
      Sum(Case When reputation_type = 'marketer' Then value Else 0 End) as marketer,
      Sum(Case When reputation_type = 'archivist' Then value Else 0 End) as archivist,
      Sum(Case When reputation_type = 'karma' Then value Else 0 End) as karma
    From
      reputable_actions
    Group By
      user_id
  ) r On u.id = r.user_id
    Left Outer Join (
    Select
      c.user_id,
      Sum(Case When c.type = 'impression' Then v.value Else 0 End) as impressions,
      Sum(Case When c.type = 'reply' Then v.value Else 0 End) as replies
    From
      comments c
        inner join -- maybe left outer?
      votes v
        on v.voteable_type = c.type And v.voteable_id = c.id
    Group By
      user_id
  ) v On u.id = v.user_id

。如果您的表的结构与此不同，请告诉我。

注释和/或投票中有多行与联接“其余”中的一行匹配。这将“乘以”结果行，并将其他聚合函数的结果与之相乘（如您已经注意到的）

最简单的解决方案是在单独的查询中获取

SUM（reviewers.value）

和

SUM（communities.value）

---

顺便说一句，如果有一个以上的

信誉良好的行为

行（同一

信誉类型

）与同一

用户

行匹配，你也会遇到同样的问题。

我想最后应该有一个GROUP BY子句？很好。我已经添加了GROUPBY子句。谢谢您提供的好例子。这有点超出我的理解力，但我慢慢地理解了。在“Coalesce（v.replies 0）as replies”的末尾，我继续得到一个语法错误，我认为这是因为v.replies没有正确创建。我尝试过使用内部连接和左侧外部连接，但都没有效果。我认为问题出在最后一行，“v On u.id=v.user\u id”；评论可以。不幸的是，我不能在这里只做c.user\u id，因为注释超出了范围。（对吗？）有什么建议可以传达这些信息吗？我试图将ID包含在一个select中。@timothythehuman这是因为我错过了v.reples和0之间的逗号，修复了nowEgads，我自己应该能够捕捉到它。不过，谢谢你的帮助。我做了一系列测试，一切都正常。这是一个巨大的帮助，它向我展示了两种更好的编写查询的方法。再次感谢！