#16211: using negated F()-expression in update query
---------------------------+-------------------------------
Reporter: wdoekes | Owner: nobody
Type: Uncategorized | Status: new
Milestone: | Component: Uncategorized
Version: 1.2 | Severity: Normal
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Easy pickings: 0
UI/UX: 0 |
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Hi,
as far as I can tell, there is currently no way to do this with the ORM:
{{{
UPDATE myapp_mymodel SET is_enabled = NOT is_enabled;
}}}
Using this:
{{{
MyModel.objects.update(is_enabled=(not F('is_enabled')))
}}}
.. becomes "is_enabled = true". And this:
{{{
MyModel.objects.update(is_enabled=~F('is_enabled'))
}}}
.. doesn't work, because the bitwise not operator is not defined on the
`ExpressionNode`.
I've done a patch against 1.2 to fix add that.
It adds a unary "NOT"-connector to the `combine_expression` in
`BaseDatabaseOperations` and it adds the `__invert__` method to the
`ExpressionNode`.
If you like this, I'll be happy to do a patch against trunk.
Regards,[[br]]
Walter Doekes[[br]]
OSSO B.V.
--
Ticket URL: <https://code.djangoproject.com/ticket/16211>
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