Build Semantic Layer Views for REST Data in APOS Live Data Gateway

APOS Live Data Gateway (LDG) is a data connection and data transformation solution that enables live data connectivity and expanded data source options for SAP Analytics Cloud and other SAP solutions. When paired with CData Connectors, users can build semantic layer views for live REST data, enabling real-time analytics on REST just like working with a relational database.

With built-in optimized data processing, the CData Connector offers unmatched performance for interacting with live REST data. When you issue complex SQL queries to REST, the driver pushes supported SQL operations, like filters and aggregations, directly to REST 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 REST data using native data types.

Download and Install the Connector Files

In order to access REST data through the APOS Live Data Gateway, you will need to download the connector files from APOS and install them on the machine hosting the Live Data Gateway. An APOS representative can deliver the necessary files.

• Install the CData DLL file (System.Data.CData.REST.dll) to the APOS Live Data Gateway installation directory (C:\Program Files\Live Data Gateway\Admin\ by default).
• Install the CData JAR file (cdata.jdbc.rest.jar) to the ConnectionTest_lib folder in the installation directory (C:\Program Files\Live Data Gateway\Admin\ConnectionTest_lib\ by default).
• Install the CData JAR file (cdata.jdbc.rest.jar) to the lib folder in the Web UI installation directory (e.g.: C:\LDG_WebUI\lib\)

Configuring the REST Connection String

Before establishing the connection to REST from the APOS Live Data Gateway, you need to configure the REST JDBC Connection String.

Built-in Connection String Designer

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

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 REST APIs as bidirectional database tables and XML/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 Format to "XML" or "JSON" and 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 REST 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 REST 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.

Your connection string will look similar to the following:

Connecting to REST & Creating a Semantic Layer View

After installing the connector files and configuring the connection string, you are ready to connect to REST in the Live Data Gateway Admin tool and build a semantic layer view in the Live Data Gateway Web UI.

Configuring the Connection to REST

1. Log into your APOS Live Data Gateway Manager
2. If you haven't already, update your APOS LDG license file
   1. Click File -> Configurations
   2. Click on the "..." Menu for the License
   3. Select the license file from the APOS team that includes your CData Connector license
3. In the APOS Live Data Gateway Manager, click "Add"
4. In the APOS Live Data Gateway On the Connection tab, configure the connection:
   • Set Data Source to "Database"
   • Set Database to "CData Drivers"
   • Set Database CData Drivers to "REST"
   • Set Connection String to the connection string configured earlier (e.g.: jdbc:REST:DataModel=Relational;URI=C:/people.xml;Format=XML;
   • Set Driver Class to "cdata.jdbc.rest.RESTDriver" (this should be set by default)
5. Click Test Connection
6. Click Save
7. Give your connection a unique prefix (e.g. "rest")
8. Highlight the newly created connection and click File -> "Approve Users For Web UI"
9. Approve the appropriate DB users to create views and click "Save"

At this point, we are ready to build our semantic layer view in the Live Data Gateway Web UI.

Creating a Semantic Layer View

1. In your browser, navigate to the APOS Live Data Gateway Portal
2. Select a Connection (e.g. "rest")
3. Since REST does not require a User or Password to authenticate, you may use whatever values you wish for User Name and Password
4. Click "Login"
5. Once connected, click "Semantic Layer" to create a new semantic layer view
6. Click "New Semantic Layer View"
7. Set the Semantic Layer View Prefix and Semantic Layer View Name
8. Click "Step 2"
9. Select the table(s) and column(s) you wish to include in your view
10. Click "Step 3"
11. Select the Measures from the available table columns
12. Click "Step 5" (we skipped the "Extra Dimensions" step)
13. Add any Variable Prompts
14. Click "Step 6"
15. Define any Table Joins
16. Click "Review"
17. Review you semantic layer view and click "Save"

With the Semantic Layer View created, you are ready to access your REST data through the APOS Live Data Gateway, enabling real-time data connectivity to REST data from SAP Analytics Cloud and other SAP solutions.

More Information & Free Evaluation

Please visit APOS Systems - APOS Solutions - Request Evaluation Software to request evaluation software or email info@apos.com for more information on working with your live REST data in APOS Live Data Gateway.