0

我想计算我对数据库中特定帖子的赞数我创建了这个简单的查询显示我对一个资源“帖子”有多少赞但是当我添加到主脚本时它会错过它

SELECT     COUNT(Likes.resourceID) AS Count_resID, Resources.Id
FROM         Likes INNER JOIN
                      Resources ON Likes.resourceID = Resources.Id
GROUP BY Resources.Id

Result 
Count_resID Id
----------- -----------
1           53
2           54
2           60
2           61
1           62

(5 row(s) affected)
SELECT     a.Id, a.summary, a.pageId, a.name, a.createdOn, COUNT(Likes.resourceID) AS Count_resID
FROM         Resources AS a INNER JOIN
                      Topics_Resources AS b ON a.Id = b.ResourceID INNER JOIN
                      Skills_Resources AS c ON a.Id = c.ResourceID INNER JOIN
                      Types AS d ON a.typeId = d.Id INNER JOIN
                      Modules AS m ON a.ModuleId = m.ModuleID INNER JOIN
                      ContentItems AS ci ON m.ModuleID = ci.ModuleID INNER JOIN
                      Tabs AS t ON t.TabID = ci.TabID INNER JOIN
                      TabModules AS tb ON t.TabID = tb.TabID INNER JOIN
                      Likes ON a.Id = Likes.resourceID LEFT OUTER JOIN
                      HtmlText AS h ON tb.ModuleID = h.ModuleID
GROUP BY a.Id, a.summary, a.pageId, a.name, a.createdOn 
Id          summary                             pageId                                                            name           createdOn                 Count_resID
----------- --------------------------------------------------------------------------------------------------------------------------------------------------------------------
53          jihuih                               http://localhost/ideapark/testpage99.aspx                        jklhjk         2013-05-10 07:24:21.833    12
54          1                                    http://localhost/ideapark/testpage33.aspx                        sdvs           2013-05-09 07:24:21.833    2
60          sdvsdv                               http://localhost/ideapark/tesCreatedate.aspx                     dsvsdv         2013-05-13 07:32:13.133    8
61          newtest                              http://localhost/ideapark/newtest.aspx                           newTest       2013-05-13 10:35:08.027     2
62          sdvsdvds                             http://localhost/ideapark/page21.aspx                            svdsvs        2013-05-14 14:06:15.603     35

(5 row(s) affected)
4

2 回答 2

1

根据您的结果更改，您用于加入表格的标准之一存在问题。您必须确保连接中的表都与基表具有一比一的比例。

于 2013-05-15T20:27:24.627 回答
1

问题是您要连接多个表，并且这些表中的多个表具有 1-n 关系。您在意想不到的地方得到笛卡尔积。

解决此问题的正确方法是在加入之前进行子查询进行汇总。

但是，您确实可以使用count(distinct). 请改用此select语句：

SELECT     a.Id, a.summary, a.pageId, a.name, a.createdOn,
           COUNT(distinct Likes.Id) AS Count_resID;

这假设每个记录likes都有一个id唯一标识它。

修复它的更好方法（特别是如果将重新使用此查询）涉及更改from连接：

                  TabModules AS tb ON t.TabID = tb.TabID INNER JOIN
                  Likes ON a.Id = Likes.resourceID LEFT OUTER JOIN

类似于：

                  . . .
                  TabModules AS tb ON t.TabID = tb.TabID INNER JOIN
                  (select l.resourceId, count(*) as NumLikes
                   from Likes l
                  ) l ON a.Id = l.resourceID LEFT OUTER JOIN
                  . . .

然后NumLikes在select子句中引用。

于 2013-05-15T20:34:34.963 回答