Access Google Data Catalog Data in Mule Applications Using the CData JDBC Driver

The CData JDBC Driver for Google Data Catalog connects Google Data Catalog data to Mule applications enabling read functionality with familiar SQL queries. The JDBC Driver allows users to easily create Mule applications to backup, transform, report, and analyze Google Data Catalog data.

This article demonstrates how to use the CData JDBC Driver for Google Data Catalog inside of a Mule project to create a Web interface for Google Data Catalog data. The application created allows you to request Google Data Catalog data using an HTTP request and have the results returned as JSON. The exact same procedure outlined below can be used with any CData JDBC Driver to create a Web interface for the hundreds of available data sources.

1. Create a new Mule Project in Anypoint Studio.
2. Add an HTTP Connector to the Message Flow.
3. Configure the address for the HTTP Connector. 👁 Add and Configure the HTTP Connector
   
4. Add a Database Select Connector to the same flow, after the HTTP Connector.
5. Create a new Connection (or edit an existing one) and configure the properties.
   • Set Connection to "Generic Connection"
   • Select the CData JDBC Driver JAR file in the Required Libraries section (e.g. cdata.jdbc.googledatacatalog.jar). 👁 Adding the JAR file (Salesforce is shown).
     
   • Set the URL to the connection string for Google Data Catalog

     Google Data Catalog uses the OAuth authentication standard. Authorize access to Google APIs on behalf on individual users or on behalf of users in a domain.

     Before connecting, specify the following to identify the organization and project you would like to connect to:

     • OrganizationId: The ID associated with the Google Cloud Platform organization resource you would like to connect to. Find this by navigating to the cloud console.

       Click the project selection drop-down, and select your organization from the list. Then, click More -> Settings. The organization ID is displayed on this page.

     • ProjectId: The ID associated with the Google Cloud Platform project resource you would like to connect to.

       Find this by navigating to the cloud console dashboard and selecting your project from the Select from drop-down. The project ID will be present in the Project info card.

     When you connect, the OAuth endpoint opens in your default browser. Log in and grant permissions to the application to completes the OAuth process. For more information, refer to the OAuth section in the Help documentation.

     Built-in Connection String Designer

     For assistance in constructing the JDBC URL, use the connection string designer built into the Google Data Catalog JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

     		java -jar cdata.jdbc.googledatacatalog.jar
     		

     Fill in the connection properties and copy the connection string to the clipboard.

   • Set the Driver class name to cdata.jdbc.googledatacatalog.GoogleDataCatalogDriver. 👁 A configured Database Connection (Salesforce is shown).
     
   • Click Test Connection.
6. Set the SQL Query Text to a SQL query to request Google Data Catalog data. For example:

   SELECT Type, DatasetName FROM Schemas WHERE ProjectId = 'bigquery-public-data'

   👁 Configure the Select object (Salesforce is Shown)
   
7. Add a Transform Message Component to the flow.
8. Set the Output script to the following to convert the payload to JSON:

   %dw 2.0
   output application/json
   ---
   payload
    

   👁 Add the Transform Message Component to the Flow
   
9. To view your Google Data Catalog data, navigate to the address you configured for the HTTP Connector (localhost:8081 by default): http://localhost:8081. The Google Data Catalog data is available as JSON in your Web browser and any other tools capable of consuming JSON endpoints.

At this point, you have a simple Web interface for working with Google Data Catalog data (as JSON data) in custom apps and a wide variety of BI, reporting, and ETL tools. Download a free, 30 day trial of the JDBC Driver for Google Data Catalog and see the CData difference in your Mule Applications today.