[BUG]: timestamp with mode string is returned as Date object instead of string -- when using Bun SQL (drizzle-orm/bun-sql)

[arvilmena]

Report hasn't been filed before.

• I have verified that the bug I'm about to report hasn't been filed before.

What version of drizzle-orm are you using?

0.43.1

What version of drizzle-kit are you using?

0.31.0

Other packages

No response

Describe the Bug

This is exactly like: #806

even if you defined timestamp mode to "string", drizzle will still convert it to "date" object

This occurs if you are importing drizzle from"drizzle-orm/bun-sql"

Will not work:

import { SQL } from "bun";
import { drizzle } from "drizzle-orm/bun-sql";
import { DB_CONFIG } from "./db.config";
import * as schema from "./schema";

const client = new SQL(DB_CONFIG.DATABASE_URL);
export const db = drizzle({ client, schema });

Will get fixed if you switch to "drizzle-orm/node-postgres"/"pg"

import { drizzle } from "drizzle-orm/node-postgres";
import { Pool } from "pg";
import { DB_CONFIG } from "./db.config";
import * as schema from "./schema";

const client = new Pool({
  connectionString: DB_CONFIG.DATABASE_URL,
});
export const db = drizzle({ client, schema });

[Benjamin-Lee]

Can confirm, ran into this myself today

[lucasthevenet]

I just encountered this issue as well. From my debugging, it looks like the Bun SQL driver returns a Date object, whereas Drizzle expects a string. As a result, when using "string" mode, Drizzle ends up returning a Date instead of a string.

Additionally, in "date" mode, Drizzle tries to map the value as UTC, but does so incorrectly. This happens because it assumes the value is a string, but it's actually a Date object. This leads to invalid date strings like:

override mapFromDriverValue = (value: string): Date | null => {
  // Since value is actually a Date object, value + "+0000" results in an invalid date string like
  // 'Thu Jun 12 2025 22:43:02 GMT-0300 (Argentina Standard Time)+0000'
  return new Date(this.withTimezone ? value : value + '+0000');
};

I've gone ahead and created a reproduction repo to make it easier to visualize the issue:

https://github.com/lucasthevenet/drizzle-timestamp-mapping-test

[AndriiSherman]

Hey everyone!

I've created this message to send in a batch to all opened issues we have, just because there are a lot of them and I want to update all of you with our current work, why issues are not responded to, and the amount of work that has been done by our team over ~8 months.

I saw a lot of issues with suggestions on how to fix something while we were not responding – so thanks everyone. Also, thanks to everyone patiently waiting for a response from us and continuing to use Drizzle!

We currently have 4 major branches with a lot of work done. Each branch was handled by different devs and teams to make sure we could make all the changes in parallel.

---

First branch is drizzle-kit rewrite

All of the work can be found on the alternation-engine branch. Here is a PR with the work done: #4439

As you can see, it has 167k added lines of code and 67k removed, which means we've completely rewritten the drizzle-kit alternation engine, the way we handle diffs for each dialect, together with expanding our test suite from 600 tests to ~9k test units for all different types of actions you can do with kit. More importantly, we changed the migration folder structure and made commutative migrations, so you won't face complex conflicts on migrations when working in a team.

What's left here:

• We are finishing handling defaults for Postgres, the last being geometry (yes, we fixed the srid issue here as well).
• We are finishing commutative migrations for all dialects.
• We are finishing up the command, so the migration flow will be as simple as drizzle-kit up for you.

Where it brings us:

• We are getting drizzle-kit into a new good shape where we can call it drizzle-kit@1.0.0!

Timeline:

• We need ~2 weeks to finish all of the above and send this branch to beta for testing.

Second big branch is a complex one with several HUGE updates

• Bringing Relational Queries v2 finally live. We've done a lot of work here to actually make it faster than RQBv1 and much better from a DX point of view. But in implementing it, we had to make another big rewrite, so we completely rewrote the drizzle-orm type system, which made it much simpler and improved type performance by ~21.4x:

(types instantiations for 3300 lines production drizzle schema + 990 lines relations)

TS v5.8.3: 728.8k -> 34.1k
TS v5.9.2: 553.7k -> 25.4k

You can read more about it here.

What's left here:

• We have 1 issue with TS that is already in progress of being fixed. The issue and Post about fixing.

Where it brings us:

• We are getting drizzle-orm into a new good shape where we can call it drizzle-orm@1.0.0!

Breaking changes:

• We will have them, but we will have open channels for everyone building on top of drizzle types, so we can guide you through all the changes.

Third branch is adding support for CockroachDB and MSSQL dialects

Support for them is already in the alternation-engine branch and will be available together with the drizzle-kit rewrite.

Summary

All of the work we are doing is crucial and should be done sooner rather than later. We've received a lot of feedback and worked really hard to find the best strategies and decisions for API, DX, architecture, etc., so we can confidently mark it as v1 and be sure we can improve it and remain flexible for all the features you are asking for, while becoming even better for everyone building on top of the drizzle API as well.

We didn't want to stay with some legacy decisions and solutions we had, and instead wanted to shape Drizzle in a way that will be best looking ahead to 2025–2026 trends (v1 will get proper effect support, etc.).

We believe that all of the effort we've put in will boost Drizzle and benefit everyone using it.

Thanks everyone, as we said, we are here to stay for a long time to build a great tool together!

Timelines

We are hoping to get v1 for drizzle in beta this fall and same timeline for latest. Right after that we can go through all of the issues and PRs and resond everyone. v1 for drizzle should close ~70% of all the bug tickets we have, so on beta release we will start marking them as closed!

[Scooter1337]

Still an issue 20 sept

[JacobSchroder]

Still an issue 30 oct

drizzle-kit@0.31.6
drizzle-orm@0.44.7

[odicho]

Thanks for fixing this, really appreciate it!