el.xwx.moe/prisma/migrations/20240125124457_added_subcollection_relations/migration.sql

-- AlterTable
ALTER TABLE "Collection" ADD COLUMN     "parentId" INTEGER;

-- AddForeignKey
ALTER TABLE "Collection" ADD CONSTRAINT "Collection_parentId_fkey" FOREIGN KEY ("parentId") REFERENCES "Collection"("id") ON DELETE SET NULL ON UPDATE CASCADE;