> For the complete documentation index, see [llms.txt](https://knowledgebase.qommentary.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://knowledgebase.qommentary.com/qommentary-writeback/advanced/concurrency.md).

# Concurrency

When multiple users are collaborating on the same Qommentary Writeback extension, there might be a risk of overriding someone else's data. To prevent these issues, Qommentary provides a versioning control at a record level.

To enable concurrency

1\. Add an extra column with the type **integer** or **datetime** in the destination table

{% hint style="info" %}
Set the appropiate type based on the database engine \
(e.g. for *SQL Server*, integer maps to **int** and datetime to **datetime**)
{% endhint %}

2\. Select the writeback extension and expand the Data Connections section

<div align="left"><img src="/files/-MZD15klC4BNjg_ZK72x" alt=""></div>

3\. Select the concurreny type&#x20;

<div align="left"><img src="/files/-MZD1VB_QwsONKtJ80d9" alt=""></div>

| Concurreny Type | Description                                                                            |
| --------------- | -------------------------------------------------------------------------------------- |
| Integer         | Qommentary will increment the value of the integer in 1 every time a record is updated |
| DateTime        | Qommentary will generate a timestamp every time a record is updated                    |

4\. Enter the name of the concurrency colum

<div align="left"><img src="/files/-MZD69hWt0bWtQbcFSQu" alt=""></div>

{% hint style="info" %}
This is the name of the column you added in Step1
{% endhint %}