Reverse Engineering Models

You can create a data model from a database or a script using the Reverse Engineering process.

This topic walks you through the steps to reverse engineer a Google BigQuery model. For detailed description of reverse engineering options, refer to the Reverse Engineering Options topic.

To reverse engineer a model:

1. In erwin Data Modeler (DM), click Actions > Reverse Engineer.
   The New Model screen appears.
   

2. Click Logical/Physical and set Database to Google BigQuery.
   

3. Click Next.
   The Reverse Engineering Wizard appears.
   
   

4. Click one of the following options:

   • Datasets: Use this option to reverse engineer a model from your dataset.

     If you click Datasets, continue to step 5.

   • Script File: Use this option to reverse engineer a model from a script. Selecting this option enables the File field. Click Browse and select the necessary script file.
     

     If you click Script File, see step 13 below.

5. Click Next.

The Connection tab appears.


6. Enter your User Name and Password.

The following table explains the connection parameters.

Parameter	Description	Additional Information
Connection Method	Specifies the type of connection you want to use. Connection String connects to your cluster using a connection string.
Connection String	Specifies the path to the secure connect JSON file in the following format: C:\<file name>.json	This option is available when Connection Method is set to Connection String

For information on creating JSON file for authentication, In Google BigQuery documentation, refer to the BigQuery APIs > BigQuery API Reference > BigQuery API Client Libraries > Setting up authentication section.

7. Click Connect.
   On successful connection, your connection information is displayed under Recent Connections.

   
   

8. Click Next.

   The Datasets tab appears. It displays a list of available datasets.
   
   

9. Under Available Datasets, select the datasets that you want to reverse engineer. Then, click .

   

   This moves the selected datasets under Selected Datasets.
   

10. Click Next.
    The Tables tab appears. It displays a list of available tables in the datasets that you selected in step 8.
    

11. Click Next.
    The Option Set tab appears. It displays the default option set. You can either use the default or a custom option set.
    

12. Click Next.
    The Detail Options tab appears. Set up appropriate options based on your requirement.
    

13. Click OK.

    The reverse engineering process starts.
    
    Once the process is complete, based on your selections, a schema is generated and a model is created.