mysql - 让 SQL 计算整个列的总和 - 我相信在分组时遇到问题

Question

所附图片显示了结果集，我将在下面留下我的代码 - 为什么我无法计算每个单元格中整个 viewTotal 列的总和？我希望 viewTotal 列下方的每个单元格都显示为 4。

我认为这是某种分组问题，尽管我在网络上找不到任何关于哪些列需要分组的具体信息。 重要的是保留所有三行 - 我不想只返回一行。也许这个标准使我试图做的事情变得更加困难？

谢谢， 埃文

Select topic_id, topic_subject, SUM(topicViews) as viewTotal, replyCount From
                        (
                        Select 
                            T.topic_id, T.topic_subject, Count(distinct Tvt.id) as topicViews, Count(Distinct R.reply_id) as replyCount, R.reply_id, R.reply_topic
                            From topic T                                                                         
                            LEFT JOIN topic_view_tracker Tvt ON
                                T.topic_id = Tvt.topic_id   
                            LEFT Join reply R ON
                                T.topic_id = R.reply_topic
                            Where   
                            T.topic_by = 10
                            Group By T.topic_id) B
                        Group By topic_id
                        Order by replyCount DESC

示例记录:

主题表

╔══════════╦════════════════════════════╦══════════╗
║ TOPIC_ID ║       TOPIC_SUBJECT        ║ TOPIC_BY ║
╠══════════╬════════════════════════════╬══════════╣
║       25 ║ School police in the night ║       10 ║
║       29 ║ The first topic, enjoy it  ║       10 ║
║       30 ║ This is a normal title...  ║       10 ║
╚══════════╩════════════════════════════╩══════════╝

TOPIC_VIEW_TRACKER 表

╔════╦════════════╦══════════╗
║ ID ║  USER_IP   ║ TOPIC_ID ║
╠════╬════════════╬══════════╣
║  1 ║ xx.xx.xx.x ║       25 ║
║  2 ║ xx.xx.xx.x ║       25 ║
║  3 ║ xx.xxx.xxx ║       29 ║
║  4 ║ xxx.xx.xx  ║       30 ║
╚════╩════════════╩══════════╝

回复表

╔══════════╦═════════════╗
║ REPLY_ID ║ REPLY_TOPIC ║
╠══════════╬═════════════╣
║        1 ║          25 ║
║        2 ║          29 ║
╚══════════╩═════════════╝

Expected output (example):

topic_id       topic subject                          view total   reply count
29         The first topic, enjoy it                    4            5
25          school police in the night                  4            4
30          this is a normal title for a topic ...      4            0

Answer 1

SELECT  x.*, 
        COALESCE(y.viewTotal, 0) viewTotal,
        COALESCE(z.replyCount, 0) replyCount
FROM    topic x
        LEFT JOIN
        (
            SELECT  a.topic_by, COUNT(b.topic_ID) viewTotal
            FROM    topic a
                    LEFT JOIN topic_view_tracker b
                        ON a.topic_ID = b.topic_ID
            GROUP   BY a.topic_by
        ) y ON x.topic_by = y.topic_by
        LEFT JOIN
        (
            SELECT  reply_topic, COUNT(*) replyCount
            FROM    reply
            GROUP   BY reply_topic
        ) z ON  x.topic_ID = z.reply_topic
WHERE   x.topic_by = 10

• SQLFiddle Demo

输出(基于提供的记录)

╔══════════╦════════════════════════════╦══════════╦═══════════╦════════════╗
║ TOPIC_ID ║       TOPIC_SUBJECT        ║ TOPIC_BY ║ VIEWTOTAL ║ REPLYCOUNT ║
╠══════════╬════════════════════════════╬══════════╬═══════════╬════════════╣
║       25 ║ School police in the night ║       10 ║         4 ║          1 ║
║       29 ║ The first topic, enjoy it  ║       10 ║         4 ║          1 ║
║       30 ║ This is a normal title...  ║       10 ║         4 ║          0 ║
╚══════════╩════════════════════════════╩══════════╩═══════════╩════════════╝