Fixes for PostreSQL support

Gemfile

@@ -18,7 +18,9 @@ gem 'rails_12factor', group: :production
 gem 'responders', '~> 2.0'
 
 # as the database for Active Record
+# choose only one
 gem 'mysql2'
+#gem 'pg'
 
 # for observing records
 gem 'rails-observers'

app/models/conference.rb

@@ -131,7 +131,7 @@ class Conference < ActiveRecord::Base
     result = []
 
     if program && program.cfp && program.events
-      submissions = program.events.group(:week).count
+      submissions = program.events.select(:week).group(:week).order(:week).count
       start_week = program.cfp.start_week
       weeks = program.cfp.weeks
       result = calculate_items_per_week(start_week, weeks, submissions)
@@ -179,7 +179,7 @@ class Conference < ActiveRecord::Base
         registration_period.start_date &&
         registration_period.end_date
 
-      reg = registrations.group(:week).count
+      reg = registrations.group(:week).order(:week).count
       start_week = get_registration_start_week
       weeks = registration_weeks
       result = calculate_items_per_week(start_week, weeks, reg)
@@ -337,8 +337,8 @@ class Conference < ActiveRecord::Base
   # ====Returns
   # * +hash+ -> user: submissions
   def self.get_top_submitter(limit = 5)
-    submitter = EventUser.where('event_role = ?', 'submitter').limit(limit).group(:user_id)
+    submitter = EventUser.select(:user_id).where('event_role = ?', 'submitter').limit(limit).group(:user_id)
-    counter = submitter.order('count_all desc').count
+    counter = submitter.order('count_all desc').count(:all)
     calculate_user_submission_hash(submitter, counter)
   end
 
@@ -348,10 +348,10 @@ class Conference < ActiveRecord::Base
   # ====Returns
   # * +hash+ -> user: submissions
   def get_top_submitter(limit = 5)
-    submitter = EventUser.joins(:event)
+    submitter = EventUser.joins(:event).select(:user_id)
         .where('event_role = ? and program_id = ?', 'submitter', Conference.find(id).program.id)
         .limit(limit).group(:user_id)
-    counter = submitter.order('count_all desc').count
+    counter = submitter.order('count_all desc').count(:all)
     Conference.calculate_user_submission_hash(submitter, counter)
   end
 
@@ -1100,7 +1100,8 @@ class Conference < ActiveRecord::Base
   def self.calculate_user_submission_hash(submitters, counter)
     result = ActiveSupport::OrderedHash.new
     counter.each do |key, value|
-      submitter = submitters.where(user_id: key).first
+      # make PG happy by including the user_id in ORDER
+      submitter = submitters.where(user_id: key).order(:user_id).first
       if submitter
         result[submitter.user] = value
       end

app/views/admin/reports/_missing_speakers.html.haml

@@ -3,7 +3,7 @@
     .page-header
       %h1
         Missing Speakers
-        = "(#{@missing_event_speakers.group(:user_id).length})"
+        = "(#{@missing_event_speakers.distinct(:user_id).length})"
       %p.text-muted
         All event speakers who haven't checked in
 .col-md-12

app/views/admin/reports/index.html.haml

@@ -17,7 +17,7 @@
       %a{href: '#missing-speakers', 'data-toggle' => 'tab'}
         Missing Speakers
         %span.label.label-danger{style: 'border-radius: 1em;'}
-          = @missing_event_speakers.group(:user_id).length
+          = @missing_event_speakers.distinct(:user_id).length
 
   .tab-content
     #all.tab-pane.active

db/schema.rb

@@ -13,17 +13,20 @@
 
 ActiveRecord::Schema.define(version: 20170531094819) do
 
+  # These are extensions that must be enabled in order to support this database
+  enable_extension "plpgsql"
+
   create_table "ahoy_events", force: :cascade do |t|
-    t.uuid     "visit_id",   limit: 16
+    t.integer  "visit_id"
     t.integer  "user_id"
     t.string   "name"
     t.text     "properties"
     t.datetime "time"
   end
 
-  add_index "ahoy_events", ["time"], name: "index_ahoy_events_on_time"
+  add_index "ahoy_events", ["time"], name: "index_ahoy_events_on_time", using: :btree
-  add_index "ahoy_events", ["user_id"], name: "index_ahoy_events_on_user_id"
+  add_index "ahoy_events", ["user_id"], name: "index_ahoy_events_on_user_id", using: :btree
-  add_index "ahoy_events", ["visit_id"], name: "index_ahoy_events_on_visit_id"
+  add_index "ahoy_events", ["visit_id"], name: "index_ahoy_events_on_visit_id", using: :btree
 
   create_table "answers", force: :cascade do |t|
     t.string   "title"
@@ -65,9 +68,9 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.integer  "rgt"
   end
 
-  add_index "comments", ["commentable_id"], name: "index_comments_on_commentable_id"
+  add_index "comments", ["commentable_id"], name: "index_comments_on_commentable_id", using: :btree
-  add_index "comments", ["commentable_type"], name: "index_comments_on_commentable_type"
+  add_index "comments", ["commentable_type"], name: "index_comments_on_commentable_type", using: :btree
-  add_index "comments", ["user_id"], name: "index_comments_on_user_id"
+  add_index "comments", ["user_id"], name: "index_comments_on_user_id", using: :btree
 
   create_table "commercials", force: :cascade do |t|
     t.string   "commercial_id"
@@ -137,7 +140,7 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.datetime "updated_at"
   end
 
-  add_index "delayed_jobs", ["priority", "run_at"], name: "delayed_jobs_priority"
+  add_index "delayed_jobs", ["priority", "run_at"], name: "delayed_jobs_priority", using: :btree
 
   create_table "difficulty_levels", force: :cascade do |t|
     t.string   "title"
@@ -190,10 +193,10 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.datetime "updated_at",  null: false
   end
 
-  add_index "event_schedules", ["event_id", "schedule_id"], name: "index_event_schedules_on_event_id_and_schedule_id", unique: true
+  add_index "event_schedules", ["event_id", "schedule_id"], name: "index_event_schedules_on_event_id_and_schedule_id", unique: true, using: :btree
-  add_index "event_schedules", ["event_id"], name: "index_event_schedules_on_event_id"
+  add_index "event_schedules", ["event_id"], name: "index_event_schedules_on_event_id", using: :btree
-  add_index "event_schedules", ["room_id"], name: "index_event_schedules_on_room_id"
+  add_index "event_schedules", ["room_id"], name: "index_event_schedules_on_room_id", using: :btree
-  add_index "event_schedules", ["schedule_id"], name: "index_event_schedules_on_schedule_id"
+  add_index "event_schedules", ["schedule_id"], name: "index_event_schedules_on_schedule_id", using: :btree
 
   create_table "event_types", force: :cascade do |t|
     t.string  "title",                                 null: false
@@ -301,7 +304,7 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.integer  "schedule_interval",    default: 15,    null: false
   end
 
-  add_index "programs", ["selected_schedule_id"], name: "index_programs_on_selected_schedule_id"
+  add_index "programs", ["selected_schedule_id"], name: "index_programs_on_selected_schedule_id", using: :btree
 
   create_table "qanswers", force: :cascade do |t|
     t.integer  "question_id"
@@ -373,8 +376,8 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.string   "resource_type"
   end
 
-  add_index "roles", ["name", "resource_type", "resource_id"], name: "index_roles_on_name_and_resource_type_and_resource_id"
+  add_index "roles", ["name", "resource_type", "resource_id"], name: "index_roles_on_name_and_resource_type_and_resource_id", using: :btree
-  add_index "roles", ["name"], name: "index_roles_on_name"
+  add_index "roles", ["name"], name: "index_roles_on_name", using: :btree
 
   create_table "rooms", force: :cascade do |t|
     t.string  "guid",     null: false
@@ -389,7 +392,7 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.datetime "updated_at", null: false
   end
 
-  add_index "schedules", ["program_id"], name: "index_schedules_on_program_id"
+  add_index "schedules", ["program_id"], name: "index_schedules_on_program_id", using: :btree
 
   create_table "splashpages", force: :cascade do |t|
     t.integer  "conference_id"
@@ -512,17 +515,17 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.boolean  "is_disabled",            default: false
   end
 
-  add_index "users", ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true
+  add_index "users", ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true, using: :btree
-  add_index "users", ["email"], name: "index_users_on_email", unique: true
+  add_index "users", ["email"], name: "index_users_on_email", unique: true, using: :btree
-  add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
+  add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true, using: :btree
-  add_index "users", ["username"], name: "index_users_on_username", unique: true
+  add_index "users", ["username"], name: "index_users_on_username", unique: true, using: :btree
 
   create_table "users_roles", force: :cascade do |t|
     t.integer "role_id"
     t.integer "user_id"
   end
 
-  add_index "users_roles", ["user_id", "role_id"], name: "index_users_roles_on_user_id_and_role_id"
+  add_index "users_roles", ["user_id", "role_id"], name: "index_users_roles_on_user_id_and_role_id", using: :btree
 
   create_table "vchoices", force: :cascade do |t|
     t.integer "vday_id"
@@ -566,10 +569,10 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.integer  "conference_id"
   end
 
-  add_index "versions", ["item_type", "item_id"], name: "index_versions_on_item_type_and_item_id"
+  add_index "versions", ["item_type", "item_id"], name: "index_versions_on_item_type_and_item_id", using: :btree
 
   create_table "visits", force: :cascade do |t|
-    t.uuid     "visitor_id",       limit: 16
+    t.uuid     "visitor_id"
     t.string   "ip"
     t.text     "user_agent"
     t.text     "referrer"
@@ -591,7 +594,7 @@ ActiveRecord::Schema.define(version: 20170531094819) do
     t.datetime "started_at"
   end
 
-  add_index "visits", ["user_id"], name: "index_visits_on_user_id"
+  add_index "visits", ["user_id"], name: "index_visits_on_user_id", using: :btree
 
   create_table "votes", force: :cascade do |t|
     t.integer  "event_id"