mysql 求和格式

Question

我想对我的属性进行评分，以限制用户只能对它评分一次。所以我在 table.

中保存评分和用户 ID

现在我想要属性的总平均评分。

我正在这样使用我的查询

SELECT SUM(rating_number) as rating_number, FORMAT((SUM(total_points) / SUM(rating_number),1) as average_rating FROM post_rating WHERE post_id = 9781 AND status = 1

但是我遇到了错误。我怎样才能得到总的平均评分。谢谢

Answer 1

使用这个

SELECT SUM(rating_number) as rating_number, 
FORMAT((SUM(total_points) / SUM(rating_number)),2) as average_rating
FROM post_rating WHERE post_id = 9781 AND status = 1

mysql 求和格式

mysql sum with format

mysql

format

sum