Connect to JSON Services in the Denodo Platform

Denodo Platform is a data virtualization product providing a single point of contact for enterprise database data. When paired with the CData JDBC Driver for JSON, Denodo users can work with live JSON services alongside other enterprise data sources. This article walks through creating a virtual data source for JSON in the Denodo Virtual DataPort Administrator.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live JSON services. When you issue complex SQL queries to JSON, the driver pushes supported SQL operations, like filters and aggregations, directly to JSON and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying allows you to work with and analyze JSON services using native data types.

Create the JSON Virtual Port

To connect to live JSON services from Denodo, you need to copy the JDBC Driver JAR file to the external library directory for Denodo and create a new JDBC Data Source from the Virtual DataPort Administrator tool.

1. Download the CData JDBC Driver for JSON installer, unzip the package, and run the JAR file to install the driver.
2. Copy the JAR File (and license file if it exists) from the installation location (typically C:\Program Files\CData\CData JDBC Driver for JSON\lib\) to the Denodo external library directory (C:\Denodo\Denodo Platform\lib-external\jdbc-drivers\cdata-json-19).
3. Open the Denodo Virtual DataPort Administrator tool and navigate to the Server Explorer tab.
4. Right-click "admin" and select New -> Data source -> JDBC.
5. Configure the JDBC Connection:
   • Name: your choice, e.g.: json
   • Database adapter: Generic
   • Driver class path: C:\Denodo\Denodo Platform\lib-external\jdbc-drivers\cdata-json-19
   • Driver class: cdata.jdbc.json.JSONDriver

   • Database URI: Set this to a JDBC URL using the necessary connection properties. For example,

     jdbc:json:URI=C:/people.json;DataModel=Relational;

     Information on creating the Database URI follows:

     Built-In Connection String Designer

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

     java -jar cdata.jdbc.json.jar

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

     See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models JSON APIs as bidirectional database tables and JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.

     After setting the URI and providing any authentication values, set DataModel to more closely match the data representation to the structure of your data.

     The DataModel property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

     • Document (default): Model a top-level, document view of your JSON data. The data provider returns nested elements as aggregates of data.
     • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
     • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

     See the Modeling JSON Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

6. Click the "Test connection" button to confirm the configuration and click Save.

View JSON Services in the VirtualPort Administrator Tool

After creating the data source, you can create a base view of JSON services for use in the Denodo Platform.

1. Click the "Create base view" button in the newly created VirtualPort (admin.JSON).
2. Expand the object tree and select the objects (tables) you wish to import.
3. Click the "Create selected" button to create views of the JSON services.
   Optional: Click "Create associations from foreign keys" to define relationships between the objects.
4. With the view(s) created, navigate to a table (cdata_json_people) in the Server Explorer and double-click the selected table.
5. In the new tab, click "Execution panel" to open a query panel.
6. Customize the query in the "Execute" tab or use the default:

   SELECT * FROM cdata_json_people CONTEXT ('i18n'='us_est', 'cache_wait_for_load'='true')
   

7. Click Execute to view the data.

With the base view created, you can now work with live JSON services like you would any other data source in Denodo Platform, for example, querying JSON in the Denodo Data Catalog.

Download a free, 30-day trial of the CData JDBC Driver for JSON and start working with your live JSON services in Denodo Platform. Reach out to our Support Team if you have any questions.