Prisma · query error · P2002

P2002: Unique constraint failed

PrismaClientKnownRequestError:
Invalid `db.user.create()` invocation:

Unique constraint failed on the fields: (`email`)

What it means

You tried to create or update a row with a value that must be unique (an email, a Stripe customer id, a slug) and another row already has it.

Common causes

• Sign-up or seed code that always calls create, even when the record exists
• A Stripe webhook delivered twice, each delivery creating the same row
• Two requests racing to create the same record

How to fix it

1. Use upsert when "create or update" is what you mean
2. Catch the error by code: error instanceof Prisma.PrismaClientKnownRequestError && error.code === "P2002", and show a friendly message
3. For webhooks, store the event id with a unique constraint and skip duplicates

await db.user.upsert({
  where: { email },
  update: { stripeCustomerId },
  create: { email, stripeCustomerId },
});

Prompt for Cursor or Claude Code

Prisma throws P2002 Unique constraint failed. Find the create or update that hits it, decide whether it should be an upsert, and otherwise catch Prisma.PrismaClientKnownRequestError with code P2002 and return a clear error to the user. Don't remove the @unique from the schema.

Not quite your error? Paste yours into the free VibeBoot Doctor or browse the Prisma error fixer.