Question

SELECT 
  COUNT(*) AS TotalUserVotes
FROM tblArticleVotes AS v 
INNER JOIN tblArticles AS a 
  ON v.ArticleID = a.ID 
     AND a.AuthorID = 13405

这总是返回0.我有一个表tblArticles，其中包含AuthorID和ID（文章的主键）。

然后我有一个文章投票表，其中包含articleID列。

鉴于用户13405，我需要了解他们所有文章中的投票数量！

要确认，目前tblArticleVotes中有一条记录5的文章ID。文章ID 5的作者ID为13405。

Answer 1

嗯...... JOIN中的AuthorID看起来很奇怪......也许这样效果更好？

SELECT COUNT(*) AS TotalUserVotes
  FROM tblArticleVotes AS v INNER JOIN
  tblArticles AS a ON v.ArticleID = a.ID
  WHERE a.AuthorID = 13405

Answer 2

尝试将“AND”更改为“WHERE”：

SELECT COUNT(*) AS TotalUserVotes
FROM tblArticleVotes AS v INNER JOIN
tblArticles AS a ON v.ArticleID = a.ID WHERE a.AuthorID = 13405

HTH

Answer 3

您的查询没有任何问题。为了解决这个问题，打破查询。

DECLARE @ArticleID int
SELECT @ArticleID = a.ID FROM tblArticles a WHERE a.AuthorID=13405

PRINT @ArticleID
SELECT * FROM tblArticleVotes where ArticleID=@ArticleID

Answer 4

试试这个：

SELECT a.AuthorID, COUNT(v.id) as votes
FROM tblArticles AS a 
LEFT JOIN tblArticleVotes AS v ON a.ID = v.ArticleID
GROUP BY a.ID
WHERE a.AuthorID = :author_id

坚持使用SQL查询来计算行数

4 个答案: