# Id Property

## Overloads

| [Id](https://help.qlik.com/en-US/sense-developer/May2026/Subsystems/NetSDKAPIref/Content/Qlik.Engine.NxDerivedField.Id.htm#Qlik_Engine_NxDerivedField_Id) |  | Identifier of the derived field.<br><br>The identifier is unique.<br><br>JSON property name: qId |
| --- | --- | --- |

[](https://help.qlik.com/en-US/sense-developer/Subsystems/NetSDKAPIref/Content/Qlik.Engine.NxDerivedField.Id.htm) [](https://help.qlik.com/en-US/sense-developer/Subsystems/NetSDKAPIref/Content/Qlik.Engine.NxDerivedField.Id.htm)

## Id

Identifier of the derived field.

The identifier is unique.

JSON property name: qId

### Declaration

```

          public string Id { get; set; }
    
  
```

### Property Value

| Type | Description |
| --- | --- |
| System.String |  |

### Implements

[INxDerivedField.Id](https://help.qlik.com/en-US/sense-developer/May2026/Subsystems/NetSDKAPIref/Content/Qlik.Engine.INxDerivedField.Id.htm#Qlik_Engine_INxDerivedField_Id)