Translate SQL queries with the translation API

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This document describes how to use the translation API in BigQuery to translate scripts written in other SQL dialects into GoogleSQL queries.

Supported task types

The translation API can translate the following SQL dialects into GoogleSQL:

• Amazon Redshift SQL - Redshift2BigQuery_Translation
• Apache HiveQL and Beeline CLI - HiveQL2BigQuery_Translation
• IBM Netezza SQL and NZPLSQL - Netezza2BigQuery_Translation
• Teradata and Teradata Vantage - Teradata2BigQuery_Translation
• Apache Spark SQL - SparkSQL2BigQuery_Translation
• Azure Synapse T-SQL - AzureSynapse2BigQuery_Translation
• MySQL SQL - MySQL2BigQuery_Translation
• Oracle SQL, PL/SQL, Exadata - Oracle2BigQuery_Translation
• PostgreSQL SQL - Postgresql2BigQuery_Translation
• Presto or Trino SQL - Presto2BigQuery_Translation
• Snowflake SQL - Snowflake2BigQuery_Translation
• SQL Server T-SQL - SQLServer2BigQuery_Translation
• Vertica SQL - Vertica2BigQuery_Translation

Required permissions

To get the permissions that you need to create translation jobs using the translation API, ask your administrator to grant you the MigrationWorkflow Editor (roles/bigquerymigration.editor) IAM role on the parent resource. For more information about granting roles, see Manage access.

This predefined role contains the permissions required to create translation jobs using the translation API. To see the exact permissions that are required, expand the Required permissions section:

Required permissions

The following permissions are required to create translation jobs using the translation API:

• bigquerymigration.workflows.create
• bigquerymigration.workflows.get

You might also be able to get these permissions with custom roles or other predefined roles.

Before you begin

Before you submit a translation job, complete the following steps:

1. Enable the BigQuery Migration API.
2. Collect the source files containing the SQL scripts and queries to be translated.
3. Upload the source files to Cloud Storage.

Enable the BigQuery Migration API

If your Google Cloud CLI project was created before February 15, 2022, enable the BigQuery Migration API as follows:

1. In the Google Cloud console, go to the BigQuery Migration API page.

   Go to BigQuery Migration API

2. Click Enable.

Note: Projects created after February 15, 2022 have this API enabled automatically.

Upload input files to Cloud Storage

If you want to use the Google Cloud console or the BigQuery Migration API to perform a translation job, you must upload the source files containing the queries and scripts you want to translate to Cloud Storage. You can also upload any metadata files or configuration YAML files to the same Cloud Storage bucket containing the source files. For more information about creating buckets and uploading files to Cloud Storage, see Create buckets and Upload objects from a filesystem.

Submit a translation job

To submit a translation job using the translation API, use the projects.locations.workflows.create method and supply an instance of the MigrationWorkflow resource with a supported task type.

Example: Create a batch translation

The following curl command creates a batch translation job where the input and output files are stored in Cloud Storage. The source_target_mapping field contains a list that maps the source literal entries to an optional relative path for the target output.

curl -d "{
  \"tasks\": {
      string: {
        \"type\": \"TYPE\",
        \"translation_details\": {
            \"target_base_uri\": \"TARGET_BASE\",
            \"source_target_mapping\": {
              \"source_spec\": {
                  \"base_uri\": \"BASE\"
              }
            },
        }
      }
  }
  }" \
  -H "Content-Type:application/json" \
  -H "Authorization: Bearer TOKEN" -X POST https://bigquerymigration.googleapis.com/v2alpha/projects/PROJECT_ID/locations/LOCATION/workflows

Replace the following:

• TYPE: the task type of the translation, which determines the source and target dialect.
• TARGET_BASE: the base URI for all translation outputs.
• BASE: the base URI for all files read as sources for translation.
• TOKEN: the token for authentication. To generate a token, use the gcloud auth print-access-token command or the OAuth 2.0 playground (use the scope https://www.googleapis.com/auth/cloud-platform).
• PROJECT_ID: the project to process the translation.
• LOCATION: the location of the project to process the translation.

The preceding command returns a response that includes a workflow ID written in the format projects/PROJECT_ID/locations/LOCATION/workflows/WORKFLOW_ID.

Example: Create an interactive translation job with string literal inputs and outputs

The following curl command creates a translation job with string literal inputs and outputs. The source_target_mapping field contains a list that maps the source directories to an optional relative path for the target output.

curl -d "{
  \"tasks\": {
      string: {
        \"type\": \"TYPE\",
        \"translation_details\": {
        \"source_target_mapping\": {
            \"source_spec\": {
              \"literal\": {
              \"relative_path\": \"PATH\",
              \"literal_string\": \"STRING\"
              }
            }
        },
        \"target_return_literals\": \"TARGETS\",
        }
      }
  }
  }" \
  -H "Content-Type:application/json" \
  -H "Authorization: Bearer TOKEN" -X POST https://bigquerymigration.googleapis.com/v2alpha/projects/PROJECT_ID/locations/LOCATION/workflows

Replace the following:

• TYPE: the task type of the translation, which determines the source and target dialect.
• PATH: the identifier of the literal entry, similar to a filename or path.
• STRING: string of literal input data (for example, SQL) to be translated.
• TARGETS: the expected targets that the user wants to be directly returned in the response in the literal format. These should be in the target URI format (for example, GENERATED_DIR + target_spec.relative_path + source_spec.literal.relative_path). Anything not in this list is not returned in the response. The generated directory, GENERATED_DIR for general SQL translations is sql/.
• TOKEN: the token for authentication. To generate a token, use the gcloud auth print-access-token command or the OAuth 2.0 playground (use the scope https://www.googleapis.com/auth/cloud-platform).
• PROJECT_ID: the project to process the translation.
• LOCATION: the location of the project to process the translation.

The preceding command returns a response that includes a workflow ID written in the format projects/PROJECT_ID/locations/LOCATION/workflows/WORKFLOW_ID.

Explore the translation output

After running the translation job, retrieve the results by specifying the translation job workflow ID using the following command:

curl \
-H "Content-Type:application/json" \
-H "Authorization:Bearer TOKEN" -X GET https://bigquerymigration.googleapis.com/v2alpha/projects/PROJECT_ID/locations/LOCATION/workflows/WORKFLOW_ID

Replace the following:

• TOKEN: the token for authentication. To generate a token, use the gcloud auth print-access-token command or the OAuth 2.0 playground (use the scope https://www.googleapis.com/auth/cloud-platform).
• PROJECT_ID: the project to process the translation.
• LOCATION: the location of the project to process the translation.
• WORKFLOW_ID: the ID generated when you create a translation workflow.