> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/reference/error-codes/mariadb-error-codes-1800-to-1899/e1851.md).

# Error 1851: Adding foreign keys needs foreign\_key\_checks=OFF

| Error Code | SQLSTATE | Error                                                   | Description                                        |
| ---------- | -------- | ------------------------------------------------------- | -------------------------------------------------- |
| 1851       | HY000    | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_FK\_CHECK | Adding foreign keys needs foreign\_key\_checks=OFF |

## Possible Causes and Solutions

{% hint style="success" %}
This article doesn't currently contain any content. [You can help!](/docs/general-resources/about/readme/contributing-documentation.md)
{% endhint %}

<sub>*This page is licensed: CC BY-SA / Gnu FDL*</sub>

{% @marketo/form formId="4316" %}