# Giving an asset a dataset

An [asset](https://dev.nominal.io/platform/data-model.md#data-model-asset) holds its datasets under [ref names](https://dev.nominal.io/platform/reference/glossary.md#ref-name "The name an asset or run gives each data source attached to it, such as default. Workbooks and checklists find channels by ref name and channel name."), so its workbooks, runs, and checklists see their channels. Ask the asset for a dataset by ref name: the first call creates it, and every call after that returns the same one, so an upload script can run again and again. A dataset that already exists can be attached instead, with a tag filter to attach only the points with that tag, as in the [tagged approach](https://dev.nominal.io/platform/data-model/organization/tagged-data.md).

## In code

**Python**

```python
from nominal.core import NominalClient

client = NominalClient.from_profile("default")
asset = client.get_asset("<ri.scout.instance.asset.identifier>")

dataset = asset.get_or_create_dataset("default")  # the ref name
```

**MATLAB**

```matlab
client = nominal.Client.fromProfile();
asset = client.assetByRid("<ri.scout.instance.asset.identifier>");

dataset = asset.getOrCreateDataset("UUT1 telemetry", "default");  % the dataset's name, then the ref name
```

### Attaching an existing dataset

**Python**

```python
from nominal.core import NominalClient

client = NominalClient.from_profile("default")
asset = client.get_asset("<ri.scout.instance.asset.identifier>")
dataset = client.get_dataset("<ri.catalog.instance.dataset.identifier>")

asset.add_dataset("default", dataset, series_tags={"<tag key>": "<tag value>"})  # optional tag filter: only points with this tag
```

**MATLAB**

```matlab
client = nominal.Client.fromProfile();
asset = client.assetByRid("<ri.scout.instance.asset.identifier>");
dataset = client.datasetByRid("<ri.catalog.instance.dataset.identifier>");

asset.addDataset(dataset, "default", Tags=struct("<tag key>", "<tag value>"));  % Tags is optional
```

**Rust**

```rust
let client = nominal::NominalClient::from_profile("default")?;
let asset_rid = "<ri.scout.instance.asset.identifier>";
let dataset_rid = "<ri.catalog.instance.dataset.identifier>";

client.assets().add_dataset(asset_rid, "default", dataset_rid).await?;
// or only the points with one tag value:
// client.assets().add_dataset_with_tags(asset_rid, "default", dataset_rid, [("<tag key>", "<tag value>")]).await?;
```

**Go**

```go
import (
	"github.com/nominal-io/nominal-api-go/api/rids"
	nominalapi "github.com/nominal-io/nominal-api-go/io/nominal/api"
	assetapi "github.com/nominal-io/nominal-api-go/scout/asset/api"
	"github.com/nominal-io/nominal-api-go/scout/assets"
	scoutrids "github.com/nominal-io/nominal-api-go/scout/rids/api"
	runapi "github.com/nominal-io/nominal-api-go/scout/run/api"
	"github.com/palantir/pkg/rid"
)

// httpClient is a conjure-go-runtime httpclient.Client for your Nominal REST API URL,
// and token is your API key as a bearertoken.Token
assetRid, _ := rid.ParseRID("<ri.scout.instance.asset.identifier>")
datasetRid, _ := rid.ParseRID("<ri.catalog.instance.dataset.identifier>")
assets.NewAssetServiceClient(httpClient).AddDataScopesToAsset(ctx, token, scoutrids.AssetRid(assetRid),
	assetapi.AddDataScopesToAssetRequest{DataScopes: []assetapi.CreateAssetDataScope{{
		DataScopeName: "default",
		DataSource:    runapi.NewDataSourceFromDataset(rids.DatasetRid(datasetRid)),
		SeriesTags:    map[nominalapi.TagName]nominalapi.TagValue{"<tag key>": "<tag value>"}, // optional
	}}})
```

## In the Nominal app

1. Open the asset. If its properties panel is hidden, open it with the panel icon at the top right, beside **NEW WORKBOOK**. Find the **Data source** section.

   ![An asset's properties panel, opened from the icon at the top right, with its Data source section and the + that adds one](https://dev.nominal.io/quickstart/_images/asset-properties-panel.png)
2. Click **+** (**Add data source**) and pick the dataset. If the asset has no data sources yet, click **ADD DATA SOURCE** instead.
3. Under **Refname**, choose or create a [ref name](https://dev.nominal.io/platform/reference/glossary.md#ref-name "The name an asset or run gives each data source attached to it, such as default. Workbooks and checklists find channels by ref name and channel name.").
4. To attach only part of a shared dataset, click **ADD TAG FILTERS**, choose the tag key, then click its value and pick the value.
5. Click **SAVE TO ASSET**.

![A dataset being attached in an asset's Data source section, with its Refname, ADD TAG FILTERS, and SAVE TO ASSET](https://dev.nominal.io/quickstart/_images/asset-attach-dataset.png)