django-debug-queries

This package provides a simple context manager for Django applications that will output the SQL queries caused by a block of code to standard output.

(To pre-empt a common question: Django Debug Toolbar lets you see the queries caused by HTTP requests to your application, but often I want to track down the queries that are used in a management command or some other context than making requests in your browser; the show_queries context manager in this package helps in those other situations.)

.. warning:: Please be aware that DEBUG will be set to True throughout the block (and restored to its previous value afterwards), so this shouldn't be used in production, for example.

If you have sqlparse installed, then the SQL will be pretty-printed to make them easier to read, so I'd recommend that you also do:

::

pip install sqlparse

Example

::

    from django_debug_queries import show_queries

    ...

        with show_queries():
            people = list(Person.objects.filter(date_of_birth__gt="2000-01-01") \
                .values('id', 'legal_name'))
            sessions = list(ParliamentarySession.objects.all())

This might output the following to standard output:

::


    --===--
    Number of queries: 2
      Query 0 (taking 0.003):
        SELECT "core_person"."id",
               "core_person"."legal_name"
        FROM "core_person"
        WHERE "core_person"."date_of_birth" > '2000-01-01'
        ORDER BY "core_person"."sort_name" ASC
      Query 1 (taking 0.005):
        SELECT "core_parliamentarysession"."id",
               "core_parliamentarysession"."created",
               "core_parliamentarysession"."updated",
               "core_parliamentarysession"."start_date",
               "core_parliamentarysession"."end_date",
               "core_parliamentarysession"."house_id",
               "core_parliamentarysession"."position_title_id",
               "core_parliamentarysession"."mapit_generation",
               "core_parliamentarysession"."name",
               "core_parliamentarysession"."slug"
        FROM "core_parliamentarysession"
        ORDER BY "core_parliamentarysession"."start_date" ASC
    End of query output.

Other options

Long query strings can take a long time to pretty-print using sqlparse, so by default SQL that is longer that 2048 characters is not formatted; you can adjust that limit with the optional sqlparse_character_limit parameter, e.g.:

::

    with show_queries(sqlparse_character_limit=8192):
        ...

If you are using multiple databases in your Django application, you can tell this to use a particular database with the optional db_alias parameter, e.g.

::

    with show_queries(db_alias='my_other_db'):
        ...