Get SQL query count during a Django shell session

问题:

Is there a way to print the number of raw SQL queries performed by the Django ORM during a Django shell session?

This sort of information is already provided by the Django debug toolbar (e.g, 5 QUERIES in 5.83MS but it's not obvious how to get it from the shell.

回答1:

You can use connection.queries:

>>> from django.conf import settings
>>> settings.DEBUG = True
>>> from django.db import connection
>>> Model.objects.count()
>>> # python 3 uses print()
>>> print(len(connection.queries))
1

回答2:

This is a slight improvement on the accepted answer. create a python file named extra_imports.py in some app (Eg some_app)

extra_imports.py

from django.conf import settings
settings.DEBUG = True
from django.db import connection, reset_queries


def num_queries(reset=True):
    print(len(connection.queries))
    if reset:
        reset_queries()

Now, If you are using shell_plus from django_extension (btw check it out if you are not using it), add following line to settings.py

SHELL_PLUS_PRE_IMPORTS = [('some_app.extra_imports', '*')]

If you are using django shell, run this inside shell

exec(open('some_app/extra_imports.py').read()) # python3
execfile('some_app/extra_imports.py').read()) # pyhton2

Now,

In [1]: User.objects.all()
In [2]: num_queries()
1

In [3]: User.objects.filter(company=Company.objects.first()).all()
In [4]: num_queries()
2

回答3:

If you have database routing and multiple connections, it's a bit trickier to count your database hits because connection.queries considers only the default connection, as far as I can tell.

To include all connections:

from django.db import connections,connection,reset_queries
from django.conf import settings
settings.DEBUG = True
...
def query_count_all()->int:
    query_total = 0
    for c in connections.all():
        query_total += len(c.queries)
    return query_total

or more concisely:

def query_count_all()->int:
   return sum(len(c.queries) for c in connections.all())

reset_queries() already handles multiple connections