SQL TABLE 的视图和条件 COUNT 条记录

Question

我正在尝试为特定查询创建一个视图，如下所示。

4Tables

1. users(user_id, name, profilepic)
2. topics (topic_id, topic_by_id, topic_title, topic_data, timestamp)
3. likes (topic_id, liked_by_id, timestamp)
4. comments (topic_id, comment_by_id, comment_text, timestamp)

现在我已经为前两个 table 创建了一个视图来获取数据。但下一步是获取点赞数和评论数，看看当前用户是否对这个主题点赞或评论。

topics Table是这里的主要table，topic_by_id是users中的user_id table和liked_by_id 和 comment_by_id 也是 user_id.

这是我到目前为止为获得前两个 table 的初始数据所做的工作。

CREATE VIEW TOPICS_VIEW AS 
SELECT topic.topic_id,
topic.topic_by_id AS TBYID,
topic.topic_title,
users.user_id AS UserID,
users.name, 
users.profiepic
FROM users,topic
WHERE user.user_id = topic.topic_by_id

现在我如何编辑此查询以包含喜欢和评论的数量并检查用户是否喜欢或评论了同一主题？

感谢任何帮助。

Answer 1

SELECT posts.post_id,
posts.post_creator_id AS Post_by_id,
users.user_id AS UserID,
users.f_name, 
users.profile_pic_url,
posts.post_title,
posts.post_text,
posts.post_image,
posts.post_location,
posts.post_timestamp,
posts.post_category,
posts.post_status,
(SELECT count(*) FROM post_likes WHERE users.user_id = post_likes.liked_user_id) as 
User_Liked,
(SELECT count(*) FROM post_comments WHERE users.user_id = 
post_comments.comment_creater_id) as User_Commented,
(SELECT count(*) FROM post_likes WHERE posts.post_id = post_likes.liked_post_id) as 
Total_Likes_On_Post,
(SELECT count(*) FROM post_comments WHERE posts.post_id = 
post_comments.comment_post_id) as Total_Comments_On_Post
FROM users,posts
WHERE users.user_id = posts.post_creator_id

SQL TABLE 的视图和条件 COUNT 条记录

SQL View of TABLE and with record for conditions COUNT

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mysql

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sql-view