Björn Kempén has written a nice post titled Simple middleware for database driven IP ban using django where he describes a method of using middleware to handle IP based banning in your Django application. This post really illustrates how easy it is to tie into the request / response cycle to add in customized functionality.
Display the SQL Django ORM is Generating
Posted on August 11, 2007
Did you ever need to display the SQL that Django is generating, within your shell? I was playing around with a problem, which I’ll write more about later, and I needed this exact functionality to help me learn how various options in the Django ORM were being translated into SQL.
I did not come up with this technique but found it while browsing around for an answer. All credit goes to DaveA.
Put this in a utilities module and just import it when needed.
def show_sql(q):
cols, sql, args = q._get_sql_clause()
return "SELECT %s %s" % (', '.join(cols), sql % tuple(args))
...and now for an example:
>>> from utils import show_sql
>>> from blog.models import Section
>>> q = Section.objects.all()
>>> show_sql(q)
'SELECT "blog_section"."id", "blog_section"."name", "blog_section"."slug",
"blog_section"."position" FROM "blog_section"
ORDER BY "blog_section"."position" ASC'
>>> q = Section.objects.filter(name__istartswith='djan')
>>> q
[<Section: Django>]
>>> show_sql(q)
u'SELECT "blog_section"."id", "blog_section"."name", "blog_section"."slug",
"blog_section"."position"
FROM "blog_section"
WHERE ("blog_section"."name" LIKE djan% ESCAPE \'\\\')
ORDER BY "blog_section"."position" ASC'
It’s been a great learning tool.
Update
As Jonathan Buchanan points out in the comments you can also use the method described in the Django FAQ:
>>> from django.db import connection
>>> connection.queries
{'time': '0.000', 'sql': u'SELECT "blog_section"."id","blog_section"."name","blog_section"."slug","blog_section"."position" FROM "blog_section" WHERE id NOT IN (SELECT DISTINCT section_id FROM blog_post) ORDER BY "blog_section"."position" ASC'}
To get the just the last query, slice the list:
>>> connection.queries[-1]
This method is also used in the SQL Log Middleware snippet that adds the SQL queries to the bottom of your templates.
