help with counter_cache

rubyonrails-talk
1

I have two models:

Items -id -name -created_by (links to user id) ...

Users -id -name -items_count ...

item.rb: belongs_to :user, :class_name => 'User', :foreign_key => 'created_by', :counter_cache => true

user.rb: has_many :items, :foreign_key => 'created_by'

2

bah...i figured it out. i didn't have a default value of 0 set in the field so it wasn't updating. now it's working!

the only thing now is that i have a couple thousand users who have 0 for the count values. what do you think is the best way i can mass update this field?

3

You can run a migration like this

def self.up

User.find(:all) do |u|

u.update_attribute :items_count, s.items.count

end

end

That will go through all your users and update the items_count field for all of them.

4

Bryce Roney wrote:

You can run a migration like this

def self.up    User.find(:all) do |u|      u.update_attribute :items_count, s.items.count    end end

That will go through all your users and update the items_count field for all of them. ~~~~~~~~~~~~~~~ Bryce Roney [ twitter ][ blog ][ myspace ][ facebook ]

thanks for the quick response!

i just ran it but it didn't seem to update anything.

just curious what is the 's' for in s.items.count?

5

Oh sorry! I was copying the code out of a project I had.

change s.items.count to u.items.count

-- Bryce Roney

6

Bryce Roney wrote:

Oh sorry! I was copying the code out of a project I had.

change s.items.count to u.items.count

-- Bryce Roney

np!

i just tried it with the new code and it says its successful again but items_count is still showing 0. i checked @user.items.count in one of my views and that works fine...must be something small. here is my output of the migration:

skulik@kuliksco-ub:/u1/app/wldev$ rake db:migrate (in /u1/app/wldev) == 20081218000000 UpdateItemsCount: migrating

7

Bryce Roney wrote:

You can run a migration like this

def self.up    User.find(:all) do |u|      u.update_attribute :items_count, s.items.count    end end

That will go through all your users and update the items_count field for all of them. ~~~~~~~~~~~~~~~ Bryce Roney [ twitter ][ blog ][ myspace ][ facebook ]

i think i found the main issue. I think there is supposed to be an each in there like:

def self.up     User.find(:all).each do |u|       u.update_attribute :items_count, u.items.count     end end

the weird thing is that now the migration is taking 8 seconds so it looks promising but the data is still not updated! if i change u.items.count to a constant like 1 it works fine, but it's not give me error messages and @user.items.count works in my views so i'm not sure what's wrong!

ah well, i guess i'll take another look at it tomorrow morning. thanks for the help so far! hopefully someone can see my silly mistake.

8

Maybe s.items.count is zero?

Cheers, Sazima

9

Sazima wrote:

Maybe s.items.count is zero?

Cheers, Sazima

On Dec 19, 5:01�am, Scott Kulik <rails-mailing-l...@andreas-s.net>

hmm...it shouldn't be since @user.items.count in my view shows the count correctly for each user.

10

Scott Kulik wrote:

Sazima wrote:

Maybe s.items.count is zero?

Cheers, Sazima

On Dec 19, 5:01�am, Scott Kulik <rails-mailing-l...@andreas-s.net>

hmm...it shouldn't be since @user.items.count in my view shows the count correctly for each user.

is there another i can do it like this but not using a migration?

i tried to create a rake task but that didn't work. here is my rake task:

skulik@kuliksco-ub:/u1/app/wldev/lib/tasks$ cat update_items_count.rake task :updateItemsCount do   User.find(:all) do |u|     u.update_attribute :items_count, s.items.count   end end

skulik@kuliksco-ub:/u1/app/wldev/lib/tasks$ rake updateItemsCount (in /u1/app/wldev) rake aborted! uninitialized constant User

(See full trace by running task with --trace)

thanks!

11

Scott Kulik wrote:

Scott Kulik wrote:

Sazima wrote:

Maybe s.items.count is zero?

Cheers, Sazima

On Dec 19, 5:01�am, Scott Kulik <rails-mailing-l...@andreas-s.net>

hmm...it shouldn't be since @user.items.count in my view shows the count correctly for each user.

is there another i can do it like this but not using a migration?

i tried to create a rake task but that didn't work. here is my rake task:

skulik@kuliksco-ub:/u1/app/wldev/lib/tasks$ cat update_items_count.rake task :updateItemsCount do   User.find(:all) do |u|     u.update_attribute :items_count, s.items.count   end end

skulik@kuliksco-ub:/u1/app/wldev/lib/tasks$ rake updateItemsCount (in /u1/app/wldev) rake aborted! uninitialized constant User

(See full trace by running task with --trace)

thanks!

got it. i had to do this:

task(:updateItemsCount => :environment) do   User.find(:all).each do |u|     u.update_attribute :items_count, u.items.count   end end

it's still not working but at least i can test easier!

12

Scott Kulik wrote:

Scott Kulik wrote:

Scott Kulik wrote:

Sazima wrote:

Maybe s.items.count is zero?

Cheers, Sazima

On Dec 19, 5:01�am, Scott Kulik <rails-mailing-l...@andreas-s.net>

hmm...it shouldn't be since @user.items.count in my view shows the count correctly for each user.

is there another i can do it like this but not using a migration?

i tried to create a rake task but that didn't work. here is my rake task:

skulik@kuliksco-ub:/u1/app/wldev/lib/tasks$ cat update_items_count.rake task :updateItemsCount do   User.find(:all) do |u|     u.update_attribute :items_count, s.items.count   end end

skulik@kuliksco-ub:/u1/app/wldev/lib/tasks$ rake updateItemsCount (in /u1/app/wldev) rake aborted! uninitialized constant User

(See full trace by running task with --trace)

thanks!

got it. i had to do this:

task(:updateItemsCount => :environment) do   User.find(:all).each do |u|     u.update_attribute :items_count, u.items.count   end end

it's still not working but at least i can test easier!

finally got the item count updated! 4 hours on this to realize i needed to remove

:counter_cache => true

since i think it was protecting the items_count field from being updated.