added invitation hash migration

migrations/tenant/0012-note-settings@add-invitation-hash.sql

@@ -0,0 +1,24 @@
+-- Create "invitation hash" column in note_settings table
+DO $$
+BEGIN
+  IF NOT EXISTS(SELECT *
+    FROM information_schema.columns
+    WHERE table_name='note_settings' and column_name='invitation_hash')
+  THEN
+      ALTER TABLE "public"."note_settings" ADD COLUMN "invitation_hash" VARCHAR(255);
+  END IF;
+END $$;
+
+-- Generate invitation hash for records with NULL invitation_hash
+DO $$
+BEGIN
+  UPDATE "public"."note_settings"
+  SET "invitation_hash" = SUBSTRING(CAST(GEN_RANDOM_UUID() AS VARCHAR), 1, 10)
+  WHERE "invitation_hash" IS NULL;
+END $$;
+
+-- Makes the column 'invitation_hash' NOT NULL
+DO $$
+BEGIN
+  ALTER TABLE "public"."note_settings" ALTER COLUMN "invitation_hash" SET NOT NULL;
+END $$;