# Setting a Table's Primary Field

A table's **Primary Field** is what is used to identify a record when it is linked to another record, or when you are choosing it from a dropdown.

In the example below we are trying to select an **Agency** record, and the Agency's name is being used as the primary field.

<figure><img src="https://319575345-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MifpIQWu0HCVYAt51oT%2Fuploads%2Fgit-blob-8d2c45bb38ff4b2833eb6d8ad09fe17505110841%2Fimage.png?alt=media" alt=""><figcaption></figcaption></figure>

### Changing a tables primary field

To change what field gets shown as a preview, you need to follow these steps:

1. Go to that table in the data table.
2. Click the field you wish to make the primary field. This will open the field's settings:

   If the field you have chosen is one of the valid fields (more on this below) there will be a button that says '**Set as primary field**'

   Simply click that and your views should automatically update.

<figure><img src="https://319575345-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MifpIQWu0HCVYAt51oT%2Fuploads%2Fgit-blob-0a121446fbbc3936e34f763466fe331050f9b614%2Fimage.png?alt=media" alt=""><figcaption></figcaption></figure>

### Why doesn't my field have the 'Set as primary field' button?

The button to change the primary field will only show up on valid fields. Firstly, only the following field types are considered valid to be the primary field:

* Text
* Numbers (Integer and Decimal)
* Single Option
* Any formula field

The second thing to consider is that some data sources sync the primary field from the external data source, for consistency. **Airtable** data sources can not change their primary field in Noloco. If you need to change it you will need to change the contents/values of your first field in Airtable.


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