Make sure your Django DEBUG setting is set to True.
Then, just do this:
>>> from django.db import connection
>>> connection.queries
[{'sql': 'SELECT polls_polls.id, polls_polls.question, polls_polls.pub_date FROM polls_polls',
'time': '0.002'}]
connection.queries is only available if DEBUG is True.
It’s a list of dictionaries in order of query execution. Each dictionary has
the following:
``sql`` -- The raw SQL statement
``time`` -- How long the statement took to execute, in seconds.
connection.queries includes all SQL statements – INSERTs, UPDATES,
SELECTs, etc. Each time your app hits the database, the query will be recorded.
Note that the SQL recorded here may be incorrectly quoted under SQLite.
If you are using multiple databases, you can use the
same interface on each member of the connections dictionary:
>>> from django.db import connections
>>> connections['my_db_alias'].queries
Yes. See Integrating with a legacy database.
If you don’t mind clearing data, your project’s manage.py utility has a
flush option to reset the database to the state it was in
immediately after syncdb was executed.
If you do care about deleting data, you’ll have to execute the ALTER TABLE
statements manually in your database.
There are external projects which handle schema updates, of which the current defacto standard is south.
No. Only single-column primary keys are supported.
But this isn’t an issue in practice, because there’s nothing stopping you from
adding other constraints (using the unique_together model option or
creating the constraint directly in your database), and enforcing the
uniqueness at that level. Single-column primary keys are needed for things such
as the admin interface to work; e.g., you need a simple way of being able to
specify an object to edit or delete.
We try to avoid adding special cases in the Django code to accommodate all the
database-specific options such as table type, etc. If you’d like to use any of
these options, create an SQL initial data file that
contains ALTER TABLE statements that do what you want to do. The initial
data files are executed in your database after the CREATE TABLE statements.
For example, if you’re using MySQL and want your tables to use the MyISAM table type, create an initial data file and put something like this in it:
ALTER TABLE myapp_mytable ENGINE=MyISAM;
As explained in the SQL initial data file documentation, this SQL file can contain arbitrary SQL, so you can make any sorts of changes you need to make.
Django isn’t known to leak memory. If you find your Django processes are
allocating more and more memory, with no sign of releasing it, check to make
sure your DEBUG setting is set to False. If DEBUG
is True, then Django saves a copy of every SQL statement it has executed.
(The queries are saved in django.db.connection.queries. See
How can I see the raw SQL queries Django is running?.)
To fix the problem, set DEBUG to False.
If you need to clear the query list manually at any point in your functions,
just call reset_queries(), like this:
from django import db
db.reset_queries()
Oct 03, 2017