---
title: "ErrorIfDuplicate"
slug: "errorifduplicate"
updated: 2026-06-17T18:08:46Z
published: 2026-06-17T18:08:46Z
canonical: "docs.datajet.app/errorifduplicate"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.datajet.app/llms.txt
> Use this file to discover all available pages before exploring further.

# ErrorIfDuplicate

Logs an error if the specified field has duplicate values.

## Parameters

| Key | Value(s) | Description |
| --- | --- | --- |
| method | `"ErrorIfDuplicate"` | Logs an error if the field contains duplicate values. |
| field | `"table.field"` | The fully qualified field to check for duplicate values. |
| project | `"MyProject"` | Name of the project. |

## Example

```json
{
  "method": "ErrorIfDuplicate",
  "field": "table.field",
  "project": "MyProject"
}
```