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Creating Tags

Why Would You Create Tags?​

Tags are informal, loosely controlled labels that help in search & discovery. They can be added to datasets, dataset schemas, or containers, for an easy way to label or categorize entities – without having to associate them to a broader business glossary or vocabulary.

For moreinformation about tags, refer to About DataHub Tags.

Goal Of This Guide​

This guide will show you how to create a tag named Deprecated.

Prerequisites​

For this tutorial, you need to deploy DataHub Quickstart and ingest sample data. For detailed steps, please refer to Datahub Quickstart Guide.

Create Tags With GraphQL​

note

Please note that there are two available endpoints (:8000, :9002) to access GraphQL. For more information about the differences between these endpoints, please refer to DataHub Metadata Service

GraphQL Explorer​

GraphQL Explorer is the fastest way to experiment with GraphQL without any dependancies. Navigate to GraphQL Explorer (http://localhost:9002/api/graphiql) and run the following query.

mutation createTag {
    createTag(input:
    {
      name: "Deprecated",
      description: "Having this tag means this column or table is deprecated."
    })
}

If you see the following response, the operation was successful:

{
  "data": {
    "createTag": "<tag_urn>"
  },
  "extensions": {}
}

CURL​

With CURL, you need to provide tokens. To generate a token, please refer to Access Token Management. With accessToken, you can run the following command.

curl --location --request POST 'http://localhost:8080/api/graphql' \
--header 'Authorization: Bearer <my-access-token>' \
--header 'Content-Type: application/json' \
--data-raw '{ "query": "mutation createTag { createTag(input: { name: \"Deprecated\", description: \"Having this tag means this column or table is deprecated.\" }) }", "variables":{}}'

Expected Response:

{ "data": { "createTag": "<tag_urn>" }, "extensions": {} }

Create Tags With Python SDK​

The following code creates a tag named Deprecated. You can refer to the full code in create_tag.py.

import logging

from datahub.emitter.mce_builder import make_tag_urn
from datahub.emitter.mcp import MetadataChangeProposalWrapper
from datahub.emitter.rest_emitter import DatahubRestEmitter

# Imports for metadata model classes
from datahub.metadata.schema_classes import TagPropertiesClass

log = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)

tag_urn = make_tag_urn("deprecated")
tag_properties_aspect = TagPropertiesClass(
    name="Deprecated",
    description="Having this tag means this column or table is deprecated.",
)

event: MetadataChangeProposalWrapper = MetadataChangeProposalWrapper(
    entityUrn=tag_urn,
    aspect=tag_properties_aspect,
)

# Create rest emitter
rest_emitter = DatahubRestEmitter(gms_server="http://localhost:8080")
rest_emitter.emit(event)
log.info(f"Created tag {tag_urn}")

We're using the MetdataChangeProposalWrapper to change entities in this example. For more information about the MetadataChangeProposal, please refer to MetadataChangeProposal & MetadataChangeLog Events

Expected Outcomes​

You can now see Deprecated tag has been created.

tag-created

What's Next?​

Now that you created a tag, how about adding it to a dataset? Here's a guide on how to add a tag on a dataset.