Why I Hate the Django ORM

Transcript

1. WHY I HATE THE DJANGO ORM Thursday, January 12, 2012
2. HI, I’M ALEX I HATE THE DJANGO ORM Thursday, January 12, 2012
3. I ALSO HELP BUILD IT (SO ALL OF THIS STUFF IS REALLY MY FAULT) Thursday, January 12, 2012
4. WHY DO I HATE IT? Thursday, January 12, 2012
5. SELECT event_type SUM(end_time - start_time) FROM event GROUP BY event_type Thursday, January 12, 2012
6. TAKING A STEP BACK Thursday, January 12, 2012
7. WHY DO WE HAVE AN ORM? DATABASE RECORDS INTO OBJECTS EXECUTE COMMON QUERIES NOT REPLACE SQL Thursday, January 12, 2012
8. WAS THAT A COMMON QUERY? Thursday, January 12, 2012
9. IT HAS A SYNTAX Event.objects.values( “event_type” ).annotate( Sum(F(“end_time”) - F(“start_time”)) ) Thursday, January 12, 2012
10. Traceback (most recent call last): File "<input>", line 1, in <module> File ".../query.py", line 741, in annotate is_summary=False) File ".../sql/query.py", line 990, in add_aggregate field_list = aggregate.lookup.split(LOOKUP_SEP) AttributeError: 'ExpressionNode' object has no attribute 'split' FFFFFFFUUUUUUUUUUUU Thursday, January 12, 2012
11. AGGREGATES TAKE STRINGS (NOT EXPRESSIONS OR ANYTHING ELSE USEFUL) Thursday, January 12, 2012
12. NO COMPOSABILITY Thursday, January 12, 2012
13. WEREN’T DESIGNED WITH EACH OTHER IN MIND MUCH LESS A COMPREHENSIVE SYSTEM Thursday, January 12, 2012
14. SQLALCHEMY session.query( TimlineEvent.event_type, func.sum(TimelineEvent.end_time - TimelineEvent.start_time) ).group_by( TimelineEvent.event_type ).all() Thursday, January 12, 2012
15. NOTICE THAT? SQLALCHEMY USES THE SAME SYNTAX FOR FIELDS, EVERYWHERE Thursday, January 12, 2012
16. DJANGO DOESN’T F(“field_name”) Aggregate(“field_name”) Q(field_name=value) filter(field_name=value) Thursday, January 12, 2012
17. STRINGS, KEYWORD ARGUMENTS, AND FUNKY ONE-LETTER OBJECTS (WITH VARYING LEVELS OF INTEROPERABILITY) Thursday, January 12, 2012
18. WHEN DO YOU USE WHICH? I HAVE NO IDEA (AND I WROTE THE DAMNED THING) Thursday, January 12, 2012
19. SIMPLE THINGS ARE SIMPLE MEDIUM THINGS ARE POSSIBLE HARD THINGS AREN’T Thursday, January 12, 2012
20. SIMPLE THINGS SHOULD BE SIMPLE HARD THINGS SHOULD BE POSSIBLE Thursday, January 12, 2012
21. SPEAKING OF SIMPLE... Event.objects.filter( start_date__hour=10 ) Thursday, January 12, 2012
22. AND OUGHT TO BE SIMPLE Event.objects.filter( start_date__hour__gt=11 ) Thursday, January 12, 2012
23. __ SYNTAX IS NEAT BUT LIMITED Thursday, January 12, 2012
24. THE IDEALS OF THE ORM ARE GOOD THE API IS GREAT FOR SIMPLE CASES Thursday, January 12, 2012
25. BUT THE INCONSISTENCIES BLEED AND THINGS THAT SHOULD BE EASY AREN’T Thursday, January 12, 2012
26. 80/20 SOLUTION BUT IT COULD BE 90/10 Thursday, January 12, 2012
27. THANKS QUESTIONS? Thursday, January 12, 2012