Added plantings_count (i.e. counter_cache) to Member

Also removed the superfluous .plantings_count method on Crop, which was
causing some confusion.

A thing we learned today: we should use .size to find the size of
ActiveRecord collections, not .count, because .count doesn't use the
cache (while .size does).

app/models/planting.rb

@@ -6,7 +6,7 @@ class Planting < ActiveRecord::Base
     :quantity, :sunniness, :planted_from, :owner_id
 
   belongs_to :garden
-  belongs_to :owner, :class_name => 'Member'
+  belongs_to :owner, :class_name => 'Member', :counter_cache => true
   belongs_to :crop, :counter_cache => true
 
   has_and_belongs_to_many :photos

db/migrate/20130826023159_add_plantings_count_to_member.rb

@@ -0,0 +1,5 @@
+class AddPlantingsCountToMember < ActiveRecord::Migration
+  def change
+    add_column :members, :plantings_count, :integer
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20130826012139) do
+ActiveRecord::Schema.define(:version => 20130826023159) do
 
   create_table "account_types", :force => true do |t|
     t.string   "name",              :null => false
@@ -116,6 +116,7 @@ ActiveRecord::Schema.define(:version => 20130826012139) do
     t.float    "longitude"
     t.boolean  "send_notification_email", :default => true
     t.text     "bio"
+    t.integer  "plantings_count"
   end
 
   add_index "members", ["confirmation_token"], :name => "index_users_on_confirmation_token", :unique => true

lib/tasks/growstuff.rake

@@ -156,6 +156,13 @@ namespace :growstuff do
       end
     end
 
+    desc "August 2013: initialize member planting counter"
+    task :initialize_member_planting_count => :environment do
+      Member.find_each do |m|
+        Member.reset_counters m.id, :plantings
+      end
+    end
+
   end
 
 end

script/deploy-tasks.sh

@@ -11,3 +11,6 @@ rake growstuff:oneoff:set_default_crop_creator
 
 echo "2013-08-26 - set planting owner"
 rake growstuff:oneoff:set_planting_owner
+
+echo "2013-08-26 - initialize member planting count"
+rake growstuff:oneoff:initialize_member_planting_count