# primaryColumnName

> Indicates the column that needs to be considered as the primary column, by ID.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine.UIElements](/engine/6000.0/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
[CreateProperty]
public string primaryColumnName { get; set; }
```

### Remarks

Needs to match a [Column](/engine/6000.0/script-reference/unityengine/uielements/column.md)'s id, otherwise will be ignored. The primary column cannot be hidden and will contain the expand arrow for tree views.