postmodern-intro

Postmodern is a Common Lisp library for interacting with PostgreSQL databases.

Postmodern has very good documentation, but I always like to have examples. This is intended to be an introduction to the library for beginners using examples. This is not intended to be an sql tutorial, a lisp tutorial or a postgresql tutorial or a replacement for the postmodern s-sql manual.

Database Tables Used in Examples

I'm generally going to use a database with three tables - countries, regions and test for the examples below. The tables can be most simply described by looking at the following create-table queries:

(query (:create-table countries
                      ((id :type int4 :primary-key t)
                       (name :type varchar :default "")
                       (region-id :type int4 :default 0)
                       (latitude :type numeric :default 0)
                       (longitude :type numeric :default 0)
                       (iso :type bpchar :default "")
                       (currency :type varchar :default "")
                       (text :type text :default "")
                      (:foreign-key (region-id) (regions id)))))

(query (:create-table regions
                      ((id :type int4 :primary-key t)
                       (name :type varchar :default ""))))


(query (:create-table test
                      ((id :type int4 :primary-key t)
                       (date :type timestamptz)(number-test :type numeric :default 0)
                       (money :type money :default 0)
                       (text :type text :default ""))))   

Comments