Raw SQL queries in Django views
The Django Documentation is really really good. You have basically two options to execute raw SQL. You can use Manager.raw()
to perform raw queries which return model instances, or you can avoid the model layer and execute custom SQL directly.
Using the raw()
manager:
>>> for p in Person.objects.raw('SELECT * FROM myapp_person'):
... print p
John Smith
Jane Jones
If you want to bypass the model layer directly you can use django.db.connection
which represents the default database connection:
def my_custom_sql():
from django.db import connection, transaction
cursor = connection.cursor()
# Data modifying operation - commit required
cursor.execute("UPDATE bar SET foo = 1 WHERE baz = %s", [self.baz])
transaction.commit_unless_managed()
# Data retrieval operation - no commit required
cursor.execute("SELECT foo FROM bar WHERE baz = %s", [self.baz])
row = cursor.fetchone()
return row
It can be done within one query if you are using PostgreSQL. If not, you can change the query accordingly and get the results.
from django.db import connection
from app.models import Picture
def results(request):
with connection.cursor() as cursor:
query = """
SELECT count(*) as all_count,
count(*) FILTER(WHERE vote = 'yes') as yes_count
FROM people_person;
"""
cursor.execute(query)
row = cursor.fetchone()
all_count, yes_count = row
>>> from django.db import connection
>>> cursor = connection.cursor()
>>> cursor.execute('''SELECT count(*) FROM people_person''')
1L
>>> row = cursor.fetchone()
>>> print row
(12L,)
>>> Person.objects.all().count()
12
use WHERE clause to filter vote for yes:
>>> cursor.execute('''SELECT count(*) FROM people_person WHERE vote = "yes"''')
1L