From 334148b26076ca33bb93d5dd98d7bac693b18b34 Mon Sep 17 00:00:00 2001
From: Luke Oldenburg <87272260+Luke-Oldenburg@users.noreply.github.com>
Date: Sun, 23 Nov 2025 20:55:42 +0000
Subject: [PATCH 1/2] [Schema] Uniquely index `event_configurations` by
 `event_id`

---
 app/models/event/configuration.rb                        | 2 +-
 ...d_unique_index_to_event_configurations_on_event_id.rb | 9 +++++++++
 db/schema.rb                                             | 4 ++--
 3 files changed, 12 insertions(+), 3 deletions(-)
 create mode 100644 db/migrate/20251123205131_add_unique_index_to_event_configurations_on_event_id.rb

diff --git a/app/models/event/configuration.rb b/app/models/event/configuration.rb
index 505c00277e..a2fe7e0547 100644
--- a/app/models/event/configuration.rb
+++ b/app/models/event/configuration.rb
@@ -16,7 +16,7 @@
 #
 # Indexes
 #
-#  index_event_configurations_on_event_id  (event_id)
+#  index_event_configurations_on_event_id  (event_id) UNIQUE
 #
 # Foreign Keys
 #
diff --git a/db/migrate/20251123205131_add_unique_index_to_event_configurations_on_event_id.rb b/db/migrate/20251123205131_add_unique_index_to_event_configurations_on_event_id.rb
new file mode 100644
index 0000000000..7c46684d83
--- /dev/null
+++ b/db/migrate/20251123205131_add_unique_index_to_event_configurations_on_event_id.rb
@@ -0,0 +1,9 @@
+class AddUniqueIndexToEventConfigurationsOnEventId < ActiveRecord::Migration[8.0]
+  disable_ddl_transaction!
+
+  def change
+    remove_index :event_configurations, :event_id
+
+    add_index :event_configurations, :event_id, unique: true, algorithm: :concurrently
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index e64679648f..bf7bf027f9 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -12,7 +12,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_11_15_104532) do
+ActiveRecord::Schema[8.0].define(version: 2025_11_23_205131) do
   create_schema "google_sheets"
 
   # These are extensions that must be enabled in order to support this database
@@ -937,7 +937,7 @@
     t.boolean "generate_monthly_announcement", default: false, null: false
     t.string "subevent_plan"
     t.datetime "updated_at", null: false
-    t.index ["event_id"], name: "index_event_configurations_on_event_id"
+    t.index ["event_id"], name: "index_event_configurations_on_event_id", unique: true
   end
 
   create_table "event_follows", force: :cascade do |t|

From c9f23bc708fd4f7e4d965ca288dcd236e78c19ab Mon Sep 17 00:00:00 2001
From: Luke Oldenburg <87272260+Luke-Oldenburg@users.noreply.github.com>
Date: Sun, 23 Nov 2025 20:56:05 +0000
Subject: [PATCH 2/2] Add rails validation

---
 app/models/event/configuration.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/app/models/event/configuration.rb b/app/models/event/configuration.rb
index a2fe7e0547..741135c631 100644
--- a/app/models/event/configuration.rb
+++ b/app/models/event/configuration.rb
@@ -30,6 +30,7 @@ class Configuration < ApplicationRecord
     validates_email_format_of :contact_email, allow_nil: true, allow_blank: true
     normalizes :contact_email, with: ->(contact_email) { contact_email.strip.downcase }
     validates :subevent_plan, inclusion: { in: -> { Event::Plan.available_plans.map(&:name) } }, allow_blank: true
+    validates :event, uniqueness: true
 
     after_save :create_or_destroy_monthly_announcement