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
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())}')
其他回答
如果你确保你的settings.py文件有:
django.core.context_processors.debug中列出的 DEBUG = True INTERNAL_IPS元组中的IP
然后您应该可以访问sql_queries变量。我在每个页面上都添加了一个页脚,如下所示:
{%if sql_queries %}
<div class="footNav">
<h2>Queries</h2>
<p>
{{ sql_queries|length }} Quer{{ sql_queries|pluralize:"y,ies" }}, {{sql_time_sum}} Time
{% ifnotequal sql_queries|length 0 %}
(<span style="cursor: pointer;" onclick="var s=document.getElementById('debugQueryTable').style;s.disp\
lay=s.display=='none'?'':'none';this.innerHTML=this.innerHTML=='Show'?'Hide':'Show';">Show</span>)
{% endifnotequal %}
</p>
<table id="debugQueryTable" style="display: none;">
<col width="1"></col>
<col></col>
<col width="1"></col>
<thead>
<tr>
<th scope="col">#</th>
<th scope="col">SQL</th>
<th scope="col">Time</th>
</tr>
</thead>
<tbody>
{% for query in sql_queries %}
<tr class="{% cycle odd,even %}">
<td>{{ forloop.counter }}</td>
<td>{{ query.sql|escape }}</td>
<td>{{ query.time }}</td>
</tr>
{% endfor %}
</tbody>
</table>
</div>
{% endif %}
通过添加一行,我得到了变量sql_time_sum
context_extras['sql_time_sum'] = sum([float(q['time']) for q in connection.queries])
到django_src/django/core/context_processors.py中的debug函数。
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
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
没有其他答案涵盖这个方法,所以:
我发现迄今为止最有用、最简单、最可靠的方法是询问您的数据库。例如,在Linux的Postgres上,你可能会这样做:
sudo su postgres
tail -f /var/log/postgresql/postgresql-8.4-main.log
每个数据库的过程略有不同。在数据库日志中,你不仅可以看到原始SQL,还可以看到django在系统上设置的任何连接或事务开销。
请参阅文档常见问题:“如何查看Django正在运行的原始SQL查询?”
django.db.connection.queries包含一个SQL查询列表:
from django.db import connection
print(connection.queries)
queryset也有一个包含要执行的查询的query属性:
print(MyModel.objects.filter(name="my name").query)
注意,查询的输出不是有效的SQL,因为:
Django从未真正插入参数:它将查询和参数分别发送到数据库适配器,由数据库适配器执行适当的操作。
来自Django错误报告#17741。
因此,不应该将查询输出直接发送到数据库。
如果你需要重置查询,例如,查看在给定的时间内有多少查询在运行,你可以使用reset_queries from django.db:
from django.db import reset_queries
from django.db import connection
reset_queries()
# Run your query here
print(connection.queries)
>>> []
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