Abstract

Reconciling old assumptions with new approaches can be difficult. This reconciliation can be especially difficult, when those assumptions and approaches correspond with one’s emerging professional identity. A musicologist turned developer, a Rubyist turned Pythonist, I know well how intrapersonal tensions can shape (or hinder) approaches to writing code. This talk confronts these tensions by describing the technical and emotional dimensions of my less-than-easy journey from SQL to the Django ORM.

Django supports two basic approaches to interacting with a database: (1) running queries with the Django database-mapper (more commonly described as the “ORM”), and (2) performing raw SQL. My first Django projects display a strong preference for the latter approach. I came to Django with very limited coding experience. I started my job at a Python shop as a freshly minted grad of Dev Bootcamp, where I had acquired some knowledge of Ruby on Rails and its ORM, but also learned about the possibilities and easeful-ness of SQL. I eschewed the Django ORM, in part because of its seeming unknowableness, but mainly because SQL was a familiar face in an unfamiliar land. In Django, I wrote SQL for simple queries (selecting with a WHERE clause), moderately challenging ones (joining multiple tables + ordering with CASE expressions), and obscenely complex ones (subqueries + aggregate functions + string manipulations). Whatever case, I generally found my queries to be transparent, flexible, and friendly.

It took over a year for me to appreciate that the Django ORM does clever and astonishing things. I eventually found joy in annotating querysets with derived values, and I stood in awe of the Prefetch object in elaborate prefetch operations. The ORM, I learned, could produce clean code and also bypass the performance loss that comes with transforming SQL results into more amenable data types (e.g., namedtuple).

In this talk, I will share some lessons in Django. But also, I will suggest strategies for evaluating solid, familiar approaches and replacing them with alternative ones.