I have the table
Here are the associations:
belongs_to :user #score model has_many :scores #user model
users has the column called
scores_count. In this column I store the sum of all values in the table
I wanted to use this way for storing the sum of all
scores in the column scores_count: :counter_cache => true
:counter_cache => true saving only the count of rows in the table
scores. Is there any similar method for storing the sum of all values from the table
scores? Or this task I have to implement by myself?
No. You'll have to implement it yourself. Counter-cache is for storing the number of associated records only. You could implement it using a callback on
Score to update the associated
User. See also How can I cache a calculated column in rails?
Further, unless you have noticeable performance issues with summing each time, avoid using a cache like this. It's just something that can easily go wrong and get out-of-date. It's not worth the trouble if you don't really need it.
You could use counter_culture gem.
class Score < ActiveRecord::Base belongs_to :user counter_culture :user, column_name: 'scores_sum', delta_column: 'score_value' end