PrismaClientKnownRequestError
I'm receiving a PrismaClientKnownRequestError with err.code === "P2002" (unique constraint violation), but err.meta.target is always undefined in the latest Prisma versions.
Previously, err.meta.target contained the list of fields that caused the constraint violation. Now that it's undefined, there is no way to determine which fields triggered the error — especially when a model has multiple unique constraints or compound unique indexes.
This creates a problem for implementing a global middleware/error handler, because we cannot identify which specific field (or combination of fields) violated the unique constraint.
Question
If err.meta.target is no longer available, what is the recommended way to retrieve the failing fields in a global error handler?
4 Replies
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You're correct: in recent versions of Prisma, especially when using the new "rust-free" query engine or certain adapters, the err.meta.target property is no longer reliably present on PrismaClientKnownRequestError with code "P2002" (unique constraint violation). This has been reported by multiple users, and the Prisma team has acknowledged that the shape of the meta object (including target) is not considered public API and should not be relied upon at this time. There is currently no official alternative or recommended way to programmatically retrieve the failing fields from the error object in a global error handler, as this information is simply not exposed in the error anymore in some environments. The Prisma team has indicated they "might bring something in its place" but have not provided a timeline or workaround yet. If you need this functionality, you may want to follow or comment on the related issues for updates and to express your use case to the team error message/format with the new rust-free prisma query engine.
For now, unfortunately, there is no supported or reliable way to extract the unique constraint fields from the error object in the latest Prisma versions. If this is a blocker, you may need to consider pinning your Prisma version to one where err.meta.target is still available, or implement application-level checks before writes as a workaround. But as of now, the knowledge sources do not provide a recommended solution for this in the latest Prisma releases.
what version this is available?
🤔 Alright, thanks for letting us know that there's still some help needed. A team member will reply to you shortly.
In the meantime, please let us know any additional info, questions, or which parts of the answer may need clarification.
export const errorDictionary = {
// Nutritionist
Nutritionist_email_key: "email",
Nutritionist_cpf_key: "cpf",
Nutritionist_crn_key: "crn",
// User
User_email_key: "email",
User_cpf_key: "cpf",
};
const originalMessage = (err.meta as any)?.driverAdapterError?.cause
?.originalMessage as string;
const match = originalMessage?.split('"');
if (match && match[1]) {
field = errorDictionary[match[1]] || "unknown";
}
I did this way to try to solve my problem, its a good approuch?