Build a PostgreSQL Interface for SAP Netweaver Gateway Data using the CData JDBC Driver

There are a vast number of PostgreSQL clients available on the Internet. From standard Drivers to BI and Analytics tools, PostgreSQL is a popular interface for data access. Using our JDBC Drivers, you can now create PostgreSQL entry-points that you can connect to from any standard client.

To access SAP Netweaver Gateway data as a PostgreSQL database, use the CData JDBC Driver for SAP Netweaver Gateway and a JDBC foreign data wrapper (FDW). In this article, we compile the FDW, install it, and query SAP Netweaver Gateway data from PostgreSQL Server.

Connect to SAP Netweaver Gateway Data as a JDBC Data Source

To connect to SAP Netweaver Gateway as a JDBC data source, you will need the following:

• Driver JAR path: The JAR is located in the lib subfolder of the installation directory.

• Driver class:

  cdata.jdbc.sapgateway.SAPGatewayDriver
  

• JDBC URL: The URL must start with "jdbc:sapgateway:" and can include any of the connection properties in name-value pairs separated with semicolons.

  SAP Gateway allows both basic and OAuth 2.0 authentication. You can use basic authentication to connect to your own account, or you can use OAuth to enable other users to retrieve data from your service with their accounts. In addition to authenticating, set the following connection properties to access SAP Gateway tables.

  • Url: Set this to the URL of your environment, or to the full URL of the service. For example, the full URL might appear as: https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/. In this example, the environment URL would just be: https://sapes5.sapdevcenter.com.
  • Namespace: Set the appropriate Service Namespace. In the example above, IWBEP is the namespace. It is optional if the full URL to the service is specified.
  • Service: Set this to the service you want to retrieve data from. In the example above, the service is GWSAMPLE_BASIC. It is not required if the full URL is specified.

  Authenticate via Basic Authentication

  In basic authentication, you use your login credentials to connect. Set the following properties:

  • User: This is the username you use to log in to SAP Gateway.
  • Password: This is the password you use to log in to SAP Gateway.

  Authenticate via OAuth Authentication

  You can connect to SAP Gateway using the embedded OAuth connectivity (without setting any additional authentication connection properties). When you connect, the OAuth endpoint opens in your browser. Log in and grant permissions to complete the OAuth process. See the OAuth section in the online Help documentation for more information on other OAuth authentication flows.

  Built-in Connection String Designer

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

  java -jar cdata.jdbc.sapgateway.jar
  

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

  👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)
  

  A typical JDBC URL is below:

  jdbc:sapgateway:User=user;Password=password;URL=https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/;InitiateOAuth=GETANDREFRESH;
  

Build the JDBC Foreign Data Wrapper

The Foreign Data Wrapper can be installed as an extension to PostgreSQL, without recompiling PostgreSQL. The jdbc2_fdw extension is used as an example (downloadable here).

1. Add a symlink from the shared object for your version of the JRE to /usr/lib/libjvm.so. For example:

   ln -s /usr/lib/jvm/java-6-openjdk/jre/lib/amd64/server/libjvm.so /usr/lib/libjvm.so
   

2. Start the build:

   make install USE_PGXS=1
   

Query SAP Netweaver Gateway Data as a PostgreSQL Database

After you have installed the extension, follow the steps below to start executing queries to SAP Netweaver Gateway data:

1. Log into your database.
2. Load the extension for the database:

   CREATE EXTENSION jdbc2_fdw;
   

3. Create a server object for SAP Netweaver Gateway:

   CREATE SERVER SAPGateway 
   FOREIGN DATA WRAPPER jdbc2_fdw OPTIONS (
   drivername 'cdata.jdbc.sapgateway.SAPGatewayDriver',
   url 'jdbc:sapgateway:User=user;Password=password;URL=https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/;InitiateOAuth=GETANDREFRESH;',
   querytimeout '15',
   jarfile '/home/MyUser/CData/CData\ JDBC\ Driver\ for\ Salesforce MyDriverEdition/lib/cdata.jdbc.sapgateway.jar'); 
   

4. Create a user mapping for the username and password of a user known to the MySQL daemon.

   CREATE USER MAPPING for postgres SERVER SAPGateway OPTIONS (
   username 'admin', 
   password 'test');
   

5. Create a foreign table in your local database:

   postgres=# CREATE FOREIGN TABLE salesorderlineitems (
   salesorderlineitems_id text,
   salesorderlineitems_ProductID text,
   salesorderlineitems_Quantity numeric) 
   SERVER SAPGateway OPTIONS (
   table_name 'salesorderlineitems');
   

You can now execute read/write commands to SAP Netweaver Gateway:

postgres=# SELECT * FROM salesorderlineitems;