Bug Report: Inserting String[] field causes Postgres malformed array literal error

[motopods]

Description and expected behavior
When inserting a record containing a String[] field using ZenStack ORM with PostgreSQL, the query fails with:

malformed array literal

The ORM appears to send a single string instead of a PostgreSQL array literal.

Schema Example

Example model:

model OrderRecord {
  id        String   @id @default(cuid())
  userId    String
  status    String
  tags      String[]
  createdAt DateTime @default(now())
}

The tags field is defined as String[].

---

Insert Code

Example insert:

await db.orderRecord.create({
  data: {
    userId: "user_123",
    status: "PENDING",
    tags: ["example_tag"],
  },
});

---

Generated SQL (from logs)

insert into "public"."OrderRecord"
("userId", "status", "tags", "id", "createdAt")
values ($1, $2, $3, $4, $5)
returning "id"

Parameters:

[
  "user_123",
  "PENDING",
  ["example_tag"],
  "rec_abc123",
  "2026-03-11T13:09:57.947Z"
]

---

Postgres Error

malformed array literal: "example_tag"

Full error log:

{
  "reason": "db-query-error",
  "dbErrorCode": "ERR_POSTGRES_SERVER_ERROR",
  "dbErrorMessage": "malformed array literal: \"example_tag\""
}

---

Expected Behavior

ZenStack should correctly serialize String[] into a PostgreSQL array.

Expected SQL parameter format:

{"example_tag"}

instead of:

"example_tag"

Environment (please complete the following information):

• ZenStack version: 3.4.5
• Database type: Postgresql
• Node.js/Bun version: bun 1.3.10
• Package manager: bun

[ymc9]

Hi @motopods , thanks for filing this, however I couldn't reproduce it with 3.4.5. Could you share a project?

[motopods]

@ymc9 Just for bun pg dialect.

model User {
    id   String   @id @default(cuid())
    tags String[]
}


import { ZenStackClient } from '@zenstackhq/orm';
import { BunPostgresDialect } from "kysely-bun-sql";
import { schema } from './zenstack/schema';

export const db = new ZenStackClient(schema, {
    dialect: new BunPostgresDialect({
        url: process.env.DATABASE_URL,
    }),
});

oven-sh/bun#22155

[motopods]

import { sql } from "kysely";
import { db } from "./db";

await db.$qb.insertInto("User").values({
    tags: sql<string>`${["Alice"]}`,
}).execute();

Also has malformed array literal error, this seems to be an issue with the bun pg dialect.

oven-sh/bun#22946

The array params should be wrapped by sql.array