-- AlterTable: 玩家账号权限与后台可查密码
ALTER TABLE "user_preferences" ADD COLUMN IF NOT EXISTS "allow_password_change" BOOLEAN NOT NULL DEFAULT true;
ALTER TABLE "user_preferences" ADD COLUMN IF NOT EXISTS "allow_username_change" BOOLEAN NOT NULL DEFAULT false;
ALTER TABLE "user_preferences" ADD COLUMN IF NOT EXISTS "managed_password" VARCHAR(128);