[英]Database schema for user reviews
I am working on user reviews with this columns: 我正在使用此列进行用户评论:
Each column can be number from 1-5. 每列可以是1-5的数字。 My question is how to calculate average grade for each column with out calling all reviews from database and calculating it every time.
我的问题是如何在不调用数据库中的所有评论并每次计算的情况下如何计算每列的平均成绩。
So I was thinking to put in product table: 所以我当时想放在产品表中:
and than do: average= communication_sum_of_grades / communication_number_of_reviews 比做:average = communication_sum_of_grades / communication_number_of_reviews
My question is if this is right approach? 我的问题是这是否正确?
If there are large number of records
and query for average reviews are very frequent
then your method will be efficient
because in this case writing will be a touch heavy
but reading will be very fast
. 如果有
large number of records
并且查询平均审阅very frequent
那么您的方法将很efficient
因为在这种情况下,书写会很touch heavy
but reading will be very fast
。 But in case the query for average reviews is not that frequent then you may go for the triditional method of fetching all rows and finding avarage. 但是,如果对平均评论的查询不是那么频繁,那么您可以使用一种获取所有行并查找平均的传统方法。
hope it helps :) 希望能帮助到你 :)
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