Hitting Teradata from Clojure
Today I worked on hitting Teradata from within clojure using clojure.java.jdbc, and I have to say it wasn't that bad. There are plenty of places that a few paragraphs of documentation could have saved me 30 mins or so, but all told, the delays due to googling weren't all that bad, and in the end I was able to get the requests working, and that's the most important part. I wanted to write it down because it's hard enough that it's not something I'll keep in memory, but it's not horrible.
First, set up the config for the parameters for the Teradata JDBC connection. I have a resources/ directory with a config.clj file in it that's read on startup. The contents of it are: (at least in part)
{:teradata {:classname "com.teradata.jdbc.TeraDriver" :subprotocol "teradata" :subname "//tdwa" :user "me" :password "secret"}}
Then, because we're using Leiningen, the jars are loaded in with the following added to the project.clj file:
[com.teradata/terajdbc4 "14.00.00.13"] [com.teradata/tdgssconfig "14.00.00.13"]
so that the next time we run leon, we'll get the jars, and they will know how to connect to the datasource.
Then I can simply make a function that hits the source:
(defn hit-teradata "" [arg1 arg2] (let [info (cfg/config :teradata)] (sql/with-connection info (sql/with-query-results rows ["select one, two from table where arg1 = ? and arg2 = ?" arg1 arg2] rows))))
Sure, the example is simplistic, but it works, and you get the idea. It's really in the config and jar referencing that I spent the most time. Once I had that working, the rest was simple JDBC within clojure.