我运行此查询包含1列(S)和我正在**#1241 - 操作数应包含1列(S)**错误:MySQL的#1241 - 操作数应在计算
SELECT `forumCategories`.`id`, `forumCategories`.`name`, `forumCategories`.`order`, `forumCategories`.`description`, `forumCategories`.`date_created`, COUNT(forumPosts.forumCategory_id) as postCount,
(SELECT `forumPosts`.*, `forumChildPosts`.`id`, `forumChildPosts`.`forumPost_id`, COUNT(forumChildPosts.forumPost_id) as childCount FROM `forumChildPosts` LEFT JOIN `forumPosts` ON `forumPosts`.`id` = `forumChildPosts`.`forumPost_id` GROUP BY `forumPosts`.`id`) AS childCount
FROM `forumCategories`
LEFT JOIN `forumPosts` ON `forumCategories`.`id` = `forumPosts`.`forumCategory_id`
GROUP BY `forumCategories`.`id`
ORDER BY `forumCategories`.`order` DESC
我有3个表:
forumCategories
forumPosts | forumPosts.forumCategory_id = forumCategories.id
forumChildPosts | forumChildPosts.forumPosts_id = forumPosts.id
我想计数论坛类别的所有讯息,和他们我要统计所有属于该论坛类别孩子的帖子。我怎样才能做到这一点?
你的外在选择查询去抓取列好,直到到'COUNT(forumPosts.forumCategory_id)AS postCount,'您要发送一个子查询后,但它试图获取多列如'childCount'。问题从它出现。 – FZE