Consume PostgreSQL OData Feeds in SAP Lumira

You can use the CData API Server to create data visualizations based on PostgreSQL data in SAP Lumira. The API Server enables connectivity to live data: dashboards and reports can be refreshed on demand. This article shows how to create a chart that is always up to date.

Set Up the API Server

If you have not already done so, download the CData API Server. Once you have installed the API Server, follow the steps below to begin producing secure PostgreSQL OData services:

Connect to PostgreSQL

To work with PostgreSQL data from SAP Lumira, we start by creating and configuring a PostgreSQL connection. Follow the steps below to configure the API Server to connect to PostgreSQL data:

1. First, navigate to the Connections page.
2. Click Add Connection and then search for and select the PostgreSQL connection. 👁 Selecting a data source (SQLite is shown)
   
3. Enter the necessary authentication properties to connect to PostgreSQL.

   To connect to PostgreSQL, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the data provider connects to the user's default database.

   SSH Connectivity for PostgreSQL

   You can use SSH (Secure Shell) to authenticate with PostgreSQL, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

   SSH Connections to PostgreSQL in Password Auth Mode

   To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

   • User: PostgreSQL User name
   • Password: PostgreSQL Password
   • Database: PostgreSQL database name
   • Server: PostgreSQL Server name
   • Port: PostgreSQL port number like 3306
   • UserSSH: "true"
   • SSHAuthMode: "Password"
   • SSHPort: SSH Port number
   • SSHServer: SSH Server name
   • SSHUser: SSH User name
   • SSHPassword: SSH Password

   SSH Connections to PostgreSQL in Public Key Auth Mode

   To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

   • User: PostgreSQL User name
   • Password: PostgreSQL Password
   • Database: PostgreSQL database name
   • Server: PostgreSQL Server name
   • Port: PostgreSQL port number like 3306
   • UserSSH: "true"
   • SSHAuthMode: "Public_Key"
   • SSHPort: SSH Port number
   • SSHServer: SSH Server name
   • SSHUser: SSH User name
   • SSHClientCret: the path for the public key certificate file
   👁 Connecting to a datasource (SQLite is shown)
   
4. After configuring the connection, click Save & Test to confirm a successful connection.

Configure API Server Users

Next, create a user to access your PostgreSQL data through the API Server. You can add and configure users on the Users page. Follow the steps below to configure and create a user:

1. On the Users page, click Add User to open the Add User dialog.
2. Next, set the Role, Username, and Privileges properties and then click Add User. 👁 Configure a new user
   
3. An Authtoken is then generated for the user. You can find the Authtoken and other information for each user on the Users page: 👁 API Server user settings
   

Creating API Endpoints for PostgreSQL

Having created a user, you are ready to create API endpoints for the PostgreSQL tables:

1. First, navigate to the API page and then click Add Table . 👁 Add tables
   
2. Select the connection you wish to access and click Next. 👁 Select the connection (SQLite is shown)
   
3. With the connection selected, create endpoints by selecting each table and then clicking Confirm. 👁 Adding tables from the connection (SQLite is shown)
   

Gather the OData Url

Having configured a connection to PostgreSQL data, created a user, and added resources to the API Server, you now have an easily accessible REST API based on the OData protocol for those resources. From the API page in API Server, you can view and copy the API Endpoints for the API:

Connect to PostgreSQL from SAP Lumira

Follow the steps below to retrieve PostgreSQL data into SAP Lumira. You can execute an SQL query or use the UI.

1. In SAP Lumira, click File -> New -> Query with SQL. The Add New Dataset dialog is displayed.
2. Expand the Generic section and click the Generic OData 2.0 Connector option.
3. In the Service Root URI box, enter the OData endpoint of the API Server. This URL will resemble the following:

   https://your-server:8080/api.rsc
   

4. In the User Name and Password boxes, enter the username and authtoken of an API user. These credentials will be used in HTTP Basic authentication. 👁 The OData endpoint and HTTP Basic authentication configured for an API user.
   

5. Select entities in the tree or enter an SQL query. This article imports PostgreSQL Orders entities.

   👁 Available entities for import. (Salesforce is shown.)
   

6. When you click Connect, SAP Lumira will generate the corresponding OData request and load the results into memory. You can then use any of the data processing tools available in SAP Lumira, such as filters, aggregates, and summary functions.

   👁 Tables of PostgreSQL data to be imported into SAP Lumira. (Salesforce Accounts are shown.)
   

Create Data Visualizations

After you have imported the data, you can create data visualizations in the Visualize room. Follow the steps below to create a basic chart.

1. In the Measures and Dimensions pane, drag measures and dimensions onto the x-axis and y-axis fields in the Visualization Tools pane. SAP Lumira automatically detects dimensions and measures from the metadata service of the API Server.

   By default, the SUM function is applied to all measures. Click the gear icon next to a measure to change the default summary.

2. In the Visualization Tools pane, select the chart type.
3. In the Chart Canvas pane, apply filters, sort by measures, add rankings, and update the chart with the current PostgreSQL data. 👁 A basic line chart. (Salesforce is shown.)