有没有办法在执行查询时显示Django正在运行的SQL语句?
MyModel.objects.all()
MyModel.objects.all().query.sql_with_params()
或者:
str(MyModel.objects.all().query)
apt-get install gdb
命令,否则会失败。此外,在shell中执行其他操作之前,我需要通过PID附加嗅探器,否则它将无法工作。除了这两个注意事项,它表现得非常出色。 - Tyler Morganimport logging
import re
from django.db import connection
logger = logging.getLogger(__name__)
def sql_logger():
logger.debug('TOTAL QUERIES: ' + str(len(connection.queries)))
logger.debug('TOTAL TIME: ' + str(sum([float(q['time']) for q in connection.queries])))
logger.debug('INDIVIDUAL QUERIES:')
for i, query in enumerate(connection.queries):
sql = re.split(r'(SELECT|FROM|WHERE|GROUP BY|ORDER BY|INNER JOIN|LIMIT)', query['sql'])
if not sql[0]: sql = sql[1:]
sql = [(' ' if i % 2 else '') + x for i, x in enumerate(sql)]
logger.debug('\n### {} ({} seconds)\n\n{};\n'.format(i, query['time'], '\n'.join(sql)))
然后,需要时我只需导入它并从任何上下文(通常是视图)中调用它,例如:
# ... other imports
from .utils import sql_logger
class IngredientListApiView(generics.ListAPIView):
# ... class variables and such
# Main function that gets called when view is accessed
def list(self, request, *args, **kwargs):
response = super(IngredientListApiView, self).list(request, *args, **kwargs)
# Call our function
sql_logger()
return response
在模板之外执行这个操作很好,因为如果你有API视图(通常是Django Rest Framework),它也适用于那里。
def str_query(qs):
"""
qs.query returns something that isn't valid SQL, this returns the actual
valid SQL that's executed: https://code.djangoproject.com/ticket/17741
"""
cursor = connections[qs.db].cursor()
query, params = qs.query.sql_with_params()
cursor.execute('EXPLAIN ' + query, params)
res = str(cursor.db.ops.last_executed_query(cursor, query, params))
assert res.startswith('EXPLAIN ')
return res[len('EXPLAIN '):]
如果您正在使用PostgreSQL,我相信这应该可以解决问题:
from django.db import connections
from app_name import models
from django.utils import timezone
# Generate a queryset, use your favorite filter, QS objects, and whatnot.
qs=models.ThisDataModel.objects.filter(user='bob',date__lte=timezone.now())
# Get a cursor tied to the default database
cursor=connections['default'].cursor()
# Get the query SQL and parameters to be passed into psycopg2, then pass
# those into mogrify to get the query that would have been sent to the backend
# and print it out. Note F-strings require python 3.6 or later.
print(f'{cursor.mogrify(*qs.query.sql_with_params())}')
如果您需要重复使用查询以进行某些自定义SQL,还有另一种非常有用的方法。我已在一个分析应用程序中使用了此方法,该应用程序远远超出了Django ORM可以轻松处理的范围,因此我将ORM生成的SQL作为子查询包含。
from django.db import connection
from myapp.models import SomeModel
queryset = SomeModel.objects.filter(foo='bar')
sql_query, params = queryset.query.as_sql(None, connection)
这将为您提供带有占位符的SQL查询及其参数元组,您可以直接将它们传递给数据库:
with connection.connection.cursor(cursor_factory=DictCursor) as cursor:
cursor.execute(sql_query, params)
data = cursor.fetchall()
from django.conf import settings
from django.db import connection
def sql_echo(method, *args, **kwargs):
settings.DEBUG = True
result = method(*args, **kwargs)
for query in connection.queries:
print(query)
return result
# HOW TO USE EXAMPLE:
#
# result = sql_echo(my_method, 'whatever', show=True)
它需要作为参数一个包含SQL查询的函数以及调用该函数所需的args和kwargs。结果它返回函数的返回值并在控制台中打印SQL查询。
要从Django查询数据库并获得正确的参数替换结果,您可以使用以下函数:
from django.db import connection
def print_database_query_formatted(query):
sql, params = query.sql_with_params()
cursor = connection.cursor()
cursor.execute('EXPLAIN ' + sql, params)
db_query = cursor.db.ops.last_executed_query(cursor, sql, params).replace('EXPLAIN ', '')
parts = '{}'.format(db_query).split('FROM')
print(parts[0])
if len(parts) > 1:
parts = parts[1].split('WHERE')
print('FROM{}'.format(parts[0]))
if len(parts) > 1:
parts = parts[1].split('ORDER BY')
print('WHERE{}'.format(parts[0]))
if len(parts) > 1:
print('ORDER BY{}'.format(parts[1]))
# USAGE
users = User.objects.filter(email='admin@admin.com').order_by('-id')
print_database_query_formatted(users.query)
输出示例
SELECT "users_user"."password", "users_user"."last_login", "users_user"."is_superuser", "users_user"."deleted", "users_user"."id", "users_user"."phone", "users_user"."username", "users_user"."userlastname", "users_user"."email", "users_user"."is_staff", "users_user"."is_active", "users_user"."date_joined", "users_user"."latitude", "users_user"."longitude", "users_user"."point"::bytea, "users_user"."default_search_radius", "users_user"."notifications", "users_user"."admin_theme", "users_user"."address", "users_user"."is_notify_when_buildings_in_radius", "users_user"."active_campaign_id", "users_user"."is_unsubscribed", "users_user"."sf_contact_id", "users_user"."is_agree_terms_of_service", "users_user"."is_facebook_signup", "users_user"."type_signup"
FROM "users_user"
WHERE "users_user"."email" = 'admin@admin.com'
ORDER BY "users_user"."id" DESC
它基于这个票务评论:https://code.djangoproject.com/ticket/17741#comment:4
from django.db.models import sql
def generate_update_sql(queryset, update_kwargs):
"""Converts queryset with update_kwargs
like : queryset.update(**update_kwargs) to UPDATE SQL"""
query = queryset.query.clone(sql.UpdateQuery)
query.add_update_values(update_kwargs)
compiler = query.get_compiler(queryset.db)
sql, params = compiler.as_sql()
return sql % params
from django.db.models import sql
def generate_delete_sql(queryset):
"""Converts select queryset to DELETE SQL """
query = queryset.query.chain(sql.DeleteQuery)
compiler = query.get_compiler(queryset.db)
sql, params = compiler.as_sql()
return sql % params
from django.db.models import sql
def generate_create_sql(model, model_data):
"""Converts queryset with create_kwargs
like if was: queryset.create(**create_kwargs) to SQL CREATE"""
not_saved_instance = model(**model_data)
not_saved_instance._for_write = True
query = sql.InsertQuery(model)
fields = [f for f in model._meta.local_concrete_fields if not isinstance(f, AutoField)]
query.insert_values(fields, [not_saved_instance], raw=False)
compiler = query.get_compiler(model.objects.db)
sql, params = compiler.as_sql()[0]
return sql % params
测试和使用
def test_generate_update_sql_with_F(self):
qs = Event.objects.all()
update_kwargs = dict(description=F('slug'))
result = generate_update_sql(qs, update_kwargs)
sql = "UPDATE `api_event` SET `description` = `api_event`.`slug`"
self.assertEqual(sql, result)
def test_generate_create_sql(self):
result = generate_create_sql(Event, dict(slug='a', app='b', model='c', action='e'))
sql = "INSERT INTO `api_event` (`slug`, `app`, `model`, `action`, `action_type`, `description`) VALUES (a, b, c, e, , )"
self.assertEqual(sql, result)
from django.db import reset_queries, connection
class ShowSQL(object):
def __enter__(self):
reset_queries()
return self
def __exit__(self, *args):
for sql in connection.queries:
print('Time: %s\nSQL: %s' % (sql['time'], sql['sql']))
那么您可以使用:
with ShowSQL() as t:
some queries <select>|<annotate>|<update> or other
它会打印