title: django.db.backends utils Example Code

category: page

slug: django-db-backends-utils-examples

sortorder: 500011170

toc: False

sidebartitle: django.db.backends utils

meta: Python example code for the utils callable from the django.db.backends module of the Django project.

utils is a callable within the django.db.backends module of the Django project.

[django-extensions](https://github.com/django-extensions/django-extensions)

([project documentation](https://django-extensions.readthedocs.io/en/latest/)

and [PyPI page](https://pypi.org/project/django-extensions/))

is a [Django](/django.html) project that adds a bunch of additional

useful commands to the `manage.py` interface. This

[GoDjango video](https://www.youtube.com/watch?v=1F6G3ONhr4k) provides a

quick overview of what you get when you install it into your Python

environment.

The django-extensions project is open sourced under the

[MIT license](https://github.com/django-extensions/django-extensions/blob/master/LICENSE).

[**django-extensions / django_extensions / management / debug_cursor.py**](https://github.com/django-extensions/django-extensions/blob/master/django_extensions/management/debug_cursor.py)

import six

import time

import traceback

from contextlib import contextmanager

import django

from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

~~from django.db.backends import utils

def monkey_patch_cursordebugwrapper(print_sql=None, print_sql_location=False, truncate=None, logger=six.print_, confprefix="DJANGO_EXTENSIONS"):

if not print_sql:

yield

else:

truncate = getattr(settings, '%s_PRINT_SQL_TRUNCATE' % confprefix, 1000)

sqlparse = None

if getattr(settings, '%s_SQLPARSE_ENABLED' % confprefix, True):

try:

import sqlparse

sqlparse_format_kwargs_defaults = dict(

reindent_aligned=True,

truncate_strings=500,

)

sqlparse_format_kwargs = getattr(settings, '%s_SQLPARSE_FORMAT_KWARGS' % confprefix, sqlparse_format_kwargs_defaults)

except ImportError:

sqlparse = None

pygments = None

if getattr(settings, '%s_PYGMENTS_ENABLED' % confprefix, True):

try:

import pygments.lexers

import pygments.formatters

pygments_formatter = getattr(settings, '%s_PYGMENTS_FORMATTER' % confprefix, pygments.formatters.TerminalFormatter)

pygments_formatter_kwargs = getattr(settings, '%s_PYGMENTS_FORMATTER_KWARGS' % confprefix, {})

except ImportError:

pass

class PrintQueryWrapperMixin:

def execute(self, sql, params=()):

starttime = time.time()

try:

~~ return utils.CursorWrapper.execute(self, sql, params)

finally:

execution_time = time.time() - starttime

raw_sql = self.db.ops.last_executed_query(self.cursor, sql, params)

if truncate:

raw_sql = raw_sql[:truncate]

if sqlparse:

raw_sql = sqlparse.format(raw_sql, **sqlparse_format_kwargs)

if pygments:

raw_sql = pygments.highlight(

raw_sql,

pygments.lexers.get_lexer_by_name("sql"),

pygments_formatter(**pygments_formatter_kwargs),

)

logger(raw_sql)

logger("Execution time: %.6fs [Database: %s]" % (execution_time, self.db.alias))

if print_sql_location:

logger("Location of SQL Call:")

logger(''.join(traceback.format_stack()))

~~ _CursorDebugWrapper = utils.CursorDebugWrapper

class PrintCursorQueryWrapper(PrintQueryWrapperMixin, _CursorDebugWrapper):

pass

try:

from django.db import connections

_force_debug_cursor = {}

for connection_name in connections:

_force_debug_cursor[connection_name] = connections[connection_name].force_debug_cursor

except Exception:

connections = None

~~ utils.CursorDebugWrapper = PrintCursorQueryWrapper

postgresql_base = None

if django.VERSION >= (3, 0):

try:

from django.db.backends.postgresql import base as postgresql_base

_PostgreSQLCursorDebugWrapper = postgresql_base.CursorDebugWrapper

class PostgreSQLPrintCursorDebugWrapper(PrintQueryWrapperMixin, _PostgreSQLCursorDebugWrapper):

pass

except (ImproperlyConfigured, TypeError):

postgresql_base = None

if postgresql_base:

postgresql_base.CursorDebugWrapper = PostgreSQLPrintCursorDebugWrapper

if connections:

for connection_name in connections:

connections[connection_name].force_debug_cursor = True

yield

~~ utils.CursorDebugWrapper = _CursorDebugWrapper

if postgresql_base:

postgresql_base.CursorDebugWrapper = _PostgreSQLCursorDebugWrapper

if connections:

for connection_name in connections:

connections[connection_name].force_debug_cursor = _force_debug_cursor[connection_name]