是否有一种方法可以在执行查询时显示Django正在运行的SQL ?


当前回答

从django获取查询结果到数据库(使用正确的参数替换) 你可以使用这个函数:

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

它基于这个票证评论:https://code.djangoproject.com/ticket/17741#comment:4

其他回答

我为此开发了一个扩展,所以你可以很容易地在你的视图函数上放一个装饰器,看看有多少查询被执行了。

如何安装:

$ pip install django-print-sql

用作上下文管理器:

from django_print_sql import print_sql

# set `count_only` to `True` will print the number of executed SQL statements only
with print_sql(count_only=False):

  # write the code you want to analyze in here,
  # e.g. some complex foreign key lookup,
  # or analyzing a DRF serializer's performance

  for user in User.objects.all()[:10]:
      user.groups.first()

装饰:用作装饰:

from django_print_sql import print_sql_decorator


@print_sql_decorator(count_only=False)  # this works on class-based views as well
def get(request):
    # your view code here

Github: https://github.com/rabbit-aaron/django-print-sql

你可以使用连接。在Django中运行原始SQL查询,如下所示:

# "store/views.py"

from django.db import transaction
from .models import Person
from django.db import connection
from django.http import HttpResponse

@transaction.atomic
def test(request):
    Person.objects.create(name="John") # INSERT
    
    qs = Person.objects.select_for_update().get(name="John") # SELECT FOR UPDATE
    qs.name = "Tom"
    qs.save() # UPDATE
    qs.delete() # DELETE
                 
    for query in connection.queries: # Here
        print(query)

    return HttpResponse("Test")

然后,原始查询打印在控制台,如下所示:

{'sql': 'INSERT INTO "store_person" ("name") VALUES (\'John\') RETURNING "store_person"."id"', 'time': '0.000'}
{'sql': 'SELECT "store_person"."id", "store_person"."name" FROM "store_person" WHERE "store_person"."name" = \'John\' LIMIT 21 FOR UPDATE', 'time': '0.000'}      
{'sql': 'UPDATE "store_person" SET "name" = \'Tom\' WHERE "store_person"."id" = 179', 'time': '0.000'}
{'sql': 'DELETE FROM "store_person" WHERE "store_person"."id" IN (179)', 'time': '0.000'}
[24/Dec/2022 06:29:32] "GET /store/test/ HTTP/1.1" 200 9

然后,把reset_queries()放在Person.objects.select_for_update()之后,如果你想只得到UPDATE和DELETE查询,而没有INSERT和SELECT FOR UPDATE查询,如下所示:

# "store/views.py"

from django.db import transaction
from .models import Person
from django.db import reset_queries
from django.db import connection
from django.http import HttpResponse

@transaction.atomic
def test(request):
    Person.objects.create(name="John") # INSERT
    
    qs = Person.objects.select_for_update().get(name="John") # SELECT FOR UPDATE
    reset_queries() # Here
    qs.name = "Tom"
    qs.save() # UPDATE
    qs.delete() # DELETE
                 
    for query in connection.queries: # Here
        print(query)

    return HttpResponse("Test")

然后,只打印UPDATE和DELETE查询,不打印INSERT和SELECT FOR UPDATE查询,如下所示:

{'sql': 'UPDATE "store_person" SET "name" = \'Tom\' WHERE "store_person"."id" = 190', 'time': '0.000'}
{'sql': 'DELETE FROM "store_person" WHERE "store_person"."id" IN (190)', 'time': '0.000'}
[24/Dec/2022 07:00:01] "GET /store/test/ HTTP/1.1" 200 9

这里已经有几个很好的答案了。

还有一种方法。

在测试中,这样做:

with self.assertNumQueries(3):
    response = self.client.post(reverse('payments:pay_list'))
    # or whatever

如果查询数量错误,则测试失败,并在控制台中打印所有原始SQL查询。

此外,此类测试有助于控制SQL查询的数量不会随着代码的更改而增加,并且数据库负载不会过多。

我相信这应该工作,如果你使用PostgreSQL:

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())}')

查询实际上嵌入在模型API中:

q = Query.objects.values('val1','val2','val_etc')

print(q.query)