# DUPLICATE_GROUP_BY — the same groupBy dimension was listed twice

Raised by `POST /api/entity/stats/{entityName}/{modelVersion}/query`. The reserved token `state` appearing twice, or the same JSONPath appearing twice, is…

<em>cyoda-go version <a href="https://github.com/Cyoda/cyoda-go/releases/tag/v0.8.4">0.8.4</a></em>

# errors.DUPLICATE_GROUP_BY

## NAME

DUPLICATE_GROUP_BY — two `groupBy` entries name the same dimension.

## SYNOPSIS

HTTP: `400` `Bad Request`. Retryable: `no`.

## DESCRIPTION

Raised by `POST /api/entity/stats/{entityName}/{modelVersion}/query`. The reserved token `state` appearing twice, or the same JSONPath appearing twice, is rejected rather than deduplicated: a repeated dimension adds a second copy of the same value to every bucket's `groupKey` and changes nothing about the grouping, so it is more likely a mistake in the request than an intent.

The message names the offending entry. Remove the repeat. Two different paths that happen to resolve to the same value at runtime are not duplicates and are accepted — the comparison is on the request entries, which are validated but never rewritten.

## SEE ALSO

- errors
- crud
- errors.MISSING_GROUP_BY
- errors.INVALID_GROUP_BY_PATH

## See also

- [`cyoda help errors`](/help/errors/) — Every error response from the Cyoda REST API carries a structured `errorCode` in the `properties` object. Multiple codes may share the same HTTP status. Programmatic handling keys on `errorCode`, not HTTP status.
- [`cyoda help crud`](/help/crud/) — Entities are instances of models. Each entity has a UUID, a model reference (`entityName`, `modelVersion`), and a lifecycle state managed by the workflow engine. Creating an entity requires the referenced model to be in `LOCKED` state. All write operations run within a Cyoda transaction and return a `transactionId` alongside the affected entity IDs.
- [`cyoda help errors MISSING_GROUP_BY`](/help/errors/missing_group_by/) — Raised by `POST /api/entity/stats/{entityName}/{modelVersion}/query`. `groupBy` is required and must carry at least one dimension: the endpoint returns one bucket per distinct group key, and there is no reading of the request that groups by nothing.
- [`cyoda help errors INVALID_GROUP_BY_PATH`](/help/errors/invalid_group_by_path/) — Raised by `POST /api/entity/stats/{entityName}/{modelVersion}/query`. Every `groupBy` entry other than `state` must match the wire JSONPath grammar — a required `$.` leader followed by dot-separated segments of ASCII letters, digits, `_` and `-`:

## Raw formats

- [`/help/errors/duplicate_group_by.json`](/help/errors/duplicate_group_by.json) — full descriptor (matches `GET /help/{topic}` envelope)
- [`/help/errors/duplicate_group_by.md`](/help/errors/duplicate_group_by.md) — body only