Ready to get started?

Learn more about the CData JDBC Driver for Open Exchange Rates or download a free trial:

Download Now

A PostgreSQL Interface for Open Exchange Rates Data

Use the Remoting features of the Open Exchange Rates JDBC Driver to create a PostgreSQL entry-point for data access.

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

Connect to Open Exchange Rates Data as a JDBC Data Source

To connect to Open Exchange Rates 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.openexchangerates.OpenExchangeRatesDriver

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

    The Open Exchange Rates API supports basic authentication with an App Id. After you register, your App Id is displayed in your account dashboard. Set this to the AppId connection property.

    Built-in Connection String Designer

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

    java -jar cdata.jdbc.openexchangerates.jar

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

    A typical JDBC URL is below:

    jdbc:openexchangerates:AppId=abc1234;

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.

  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 Open Exchange Rates Data as a PostgreSQL Database

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

  1. Log into your database.
  2. Load the extension for the database: CREATE EXTENSION jdbc2_fdw;
  3. Create a server object for Open Exchange Rates: CREATE SERVER OpenExchangeRates FOREIGN DATA WRAPPER jdbc2_fdw OPTIONS ( drivername 'cdata.jdbc.openexchangerates.OpenExchangeRatesDriver', url 'jdbc:openexchangerates:AppId=abc1234;', querytimeout '15', jarfile '/home/MyUser/CData/CData\ JDBC\ Driver\ for\ Salesforce MyDriverEdition/lib/cdata.jdbc.openexchangerates.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 OpenExchangeRates OPTIONS ( username 'admin', password 'test');
  5. Create a foreign table in your local database: postgres=# CREATE FOREIGN TABLE projects ( projects_id text, projects_Id text, projects_Statistics_ViewCount numeric) SERVER OpenExchangeRates OPTIONS ( table_name 'projects');
You can now execute SELECT commands to Open Exchange Rates: postgres=# SELECT * FROM projects;