Build a PostgreSQL Interface for eBay 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 eBay data as a PostgreSQL database, use the CData JDBC Driver for eBay and a JDBC foreign data wrapper (FDW). In this article, we compile the FDW, install it, and query eBay data from PostgreSQL Server.

Connect to eBay Data as a JDBC Data Source

To connect to eBay 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.ebay.EbayDriver
  

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

  If you will be accessing your own account, you can generate an OAuthAccessToken from your developer account dashboard. You can also allow other users to securely access their own accounts.

  Both of these methods require you to create an application key set to obtain values for the following connection properties: AppId, CertId, DevId, and SiteId.

  The user consent flow additionally requires the RuName and CallbackURL.

  See the "Getting Started" chapter in the help documentation for a guide to using OAuth.

  Built-in Connection String Designer

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

  java -jar cdata.jdbc.ebay.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:ebay:AppId=MyAppId;CertId=MyCertId;DevId=MyDevId;SiteId=MySiteId;RuName=MyRuName;CallbackURL=http://localhost:33333;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 eBay Data as a PostgreSQL Database

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

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

   CREATE EXTENSION jdbc2_fdw;
   

3. Create a server object for eBay:

   CREATE SERVER Ebay 
   FOREIGN DATA WRAPPER jdbc2_fdw OPTIONS (
   drivername 'cdata.jdbc.ebay.EbayDriver',
   url 'jdbc:ebay:AppId=MyAppId;CertId=MyCertId;DevId=MyDevId;SiteId=MySiteId;RuName=MyRuName;CallbackURL=http://localhost:33333;InitiateOAuth=GETANDREFRESH;',
   querytimeout '15',
   jarfile '/home/MyUser/CData/CData\ JDBC\ Driver\ for\ Salesforce MyDriverEdition/lib/cdata.jdbc.ebay.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 Ebay OPTIONS (
   username 'admin', 
   password 'test');
   

5. Create a foreign table in your local database:

   postgres=# CREATE FOREIGN TABLE itemlisting (
   itemlisting_id text,
   itemlisting_Title text,
   itemlisting_HitCount numeric) 
   SERVER Ebay OPTIONS (
   table_name 'itemlisting');
   

You can now execute read/write commands to eBay:

postgres=# SELECT * FROM itemlisting;