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

Connect to Perigon Data as a JDBC Data Source

To connect to Perigon 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.api.APIDriver
  

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

  Using API Key Authentication

  To use the Perigon API, you need to obtain an API key from your Perigon account. Navigate to the Perigon dashboard and generate an API key from your account settings.

  After setting the following connection properties, you are ready to connect:

  • AuthScheme: Set this to APIKey.
  • APIKey: Set this to your Perigon API key.

  Example connection string:

  Profile=C:\profiles\Perigon.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_api_key"
  

  Available Tables

  The Perigon profile provides access to the following tables:

  • Articles - News articles retrieved from the Perigon news intelligence API
  • Headlines - Story clusters grouping related headline articles
  • Sources - News sources tracked by the Perigon news intelligence API
  • Journalists - Journalist profiles tracked by the Perigon news intelligence API

  Built-in Connection String Designer

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

  java -jar cdata.jdbc.api.jar
  

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

  

  A typical JDBC URL is below:

  jdbc:api:Profile=C:\profiles\Perigon.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_api_key"
  

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 Perigon Data as a PostgreSQL Database

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

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

   CREATE EXTENSION jdbc2_fdw;
   

3. Create a server object for Perigon:

   CREATE SERVER API 
   FOREIGN DATA WRAPPER jdbc2_fdw OPTIONS (
   drivername 'cdata.jdbc.api.APIDriver',
   url 'jdbc:api:Profile=C:\profiles\Perigon.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_api_key"',
   querytimeout '15',
   jarfile '/home/MyUser/CData/CData\ JDBC\ Driver\ for\ Salesforce MyDriverEdition/lib/cdata.jdbc.api.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 API OPTIONS (
   username 'admin', 
   password 'test');
   

5. Create a foreign table in your local database:

   postgres=# CREATE FOREIGN TABLE articles (
   articles_id text,
   articles_ text,
   articles_ numeric) 
   SERVER API OPTIONS (
   table_name 'articles');
   

postgres=# SELECT * FROM articles;