---
name: "tech-d1-insert-returning-not-a-write"
title: "D1 INSERT RETURNING is not a write API via .first()"
description: "Cloudflare D1 INSERT/UPDATE RETURNING + .first() returns empty results; persist with .run() or batch()"
type: "tech"
category: "cloudflare"
tags: ["tech", "cloudflare", "workers", "d1"]
related: ["[[project-news]]"]
sources: ["https://developers.cloudflare.com/d1/worker-api/d1-database/"]
---
Cloudflare D1 treats `INSERT`/`UPDATE` as writes. `stmt.first()` is a read helper and comes back empty for those statements even with `RETURNING`. A persist path that gates success on the RETURNING row will fail-closed after the write never looks persisted.

Write with `D1PreparedStatement.run()` (or `D1Database.batch()` of prepared statements), then confirm with a later `SELECT`. Do not widen `batch()` on a local D1 wrapper to a broader union — `Env.DB.batch` is `D1PreparedStatement[]` only and a wider type makes the binding unassignable.

Docs: [D1 Database API](https://developers.cloudflare.com/d1/worker-api/d1-database/).