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

Connect to Postmark Data as a JDBC Data Source

To connect to Postmark 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

  Postmark uses server API tokens to authenticate requests. Each Postmark server has its own API token, which controls access to messages, bounces, templates, and statistics associated with that server.

  To obtain your Server API Token, log in to your Postmark account and navigate to the server you want to connect to. Go to API Tokens under the server settings and copy the token labeled Server API token.

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

  • AuthScheme: Set this to APIKey.
  • APIKey: Set this to your Postmark Server API Token. This value is sent as the X-Postmark-Server-Token header on every request.

  Example connection string:

  Profile=C:\profiles\Postmark.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your-server-api-token"
  

  Connecting to Postmark

  Once the authentication is configured, you can connect to Postmark and query data from any of the available tables such as OutboundMessages, Bounces, and Templates.

  Built-in Connection String Designer

  For assistance in constructing the JDBC URL, use the connection string designer built into the Postmark 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\Postmark.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your-server-api-token"
  

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 Postmark Data as a PostgreSQL Database

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

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

   CREATE EXTENSION jdbc2_fdw;
   

3. Create a server object for Postmark:

   CREATE SERVER API 
   FOREIGN DATA WRAPPER jdbc2_fdw OPTIONS (
   drivername 'cdata.jdbc.api.APIDriver',
   url 'jdbc:api:Profile=C:\profiles\Postmark.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your-server-api-token"',
   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 bounces (
   bounces_id text,
   bounces_ text,
   bounces_ numeric) 
   SERVER API OPTIONS (
   table_name 'bounces');
   

postgres=# SELECT * FROM bounces;