我想对连接表中的值使用 where 语句。想不通:
SELECT item.*, count(articles.authorid) AS articlecount
FROM #_authors AS item
LEFT JOIN #_articles AS articles ON (articles.authorid = item.id)
WHERE item.published=1
AND articlecount>3
ORDER BY articlecount DESC
orderby 工作正常，但是当我添加“AND articlecount>3”时出现错误:“#1054 - ‘where 子句’中的未知列‘articlecount’”。
在 articlecount 中包含 WHERE 的最佳方法是什么？提前致谢!
最佳答案
对于聚合列，您可以使用 HAVING，如下所示:
SELECT item.*, count(articles.authorid) AS articlecount
FROM #_authors AS item
LEFT JOIN #_articles AS articles ON (articles.authorid = item.id)
WHERE item.published=1
GROUP BY 1,2,3,4,5,6,7,8 -- assuming there are 8 columns in item
HAVING count(articles.authorid) > 3
ORDER BY 9 DESC -- assuming there are 8 columns in item
关于mysql - 在 where 子句中使用连接值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6994696/