---
title: "Interface IToOneRelation"
slug: "sdk--stylelabs.m.sdk.contracts.base.itoonerelation"
abstract: ""
---
# Interface IToOneRelation

Base interface for relation that are associated with only one entity.

## Inherited Members

[IRelation.Role](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.irelation.html)

[IRelation.Properties](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.irelation.html)

[IRelation.GetIds()](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.irelation.html)

[IRelation.SetIds(IEnumerable<long>)](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.irelation.html)

[IRelation.SetIdentifiersAsync(IEnumerable<string>)](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.irelation.html)

[IRelation.Clear()](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.irelation.html)

[IMember.Name](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.imember.html)

[IMember.DefinitionType](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.base.imember.html)

[IDirtyTracking.IsTracking](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.dirtytracking.idirtytracking.html)

[IDirtyTracking.IsDirty](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.dirtytracking.idirtytracking.html)

[IDirtyTracking.StartTracking()](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.dirtytracking.idirtytracking.html)

[IDirtyTracking.MarkClean()](https://doc.sitecore.com/ch/en/developers/api-reference/sdk--stylelabs.m.sdk.contracts.dirtytracking.idirtytracking.html)

## Namespace: StylelabsStylelabs.MSdkStylelabs.M.Sdk.ContractsBase

## Assembly: Stylelabs.M.Sdk.dll

## Syntax

```csharp
public interface IToOneRelation : IRelation, IMember, IDirtyTracking
```

## Methods

### GetId()

Gets the value of the relation.

#### Declaration

```csharp
long? GetId()
```

#### Returns

| Type | Description |
| --- | --- |
| long | An id. |

### SetId(long?)

Sets the value of the relation.

#### Declaration

```csharp
void SetId(long? id)
```

#### Parameters

| Type | Name | Description |
| --- | --- | --- |
| long | id | The id. |

### SetIdentifierAsync(string)

Sets the value of the relation.

#### Declaration

```csharp
Task SetIdentifierAsync(string identifier)
```

#### Parameters

| Type | Name | Description |
| --- | --- | --- |
| string | identifier | The identifier. |

#### Returns

| Type | Description |
| --- | --- |
| Task | A representing the asynchronous operation. |