If you have at least one non-default db, but no default db, no dummy
default will be created for you, and the `DEFAULT_DB_ALIAS` key will
not be present. Under these circumstances, referencing the `databases`
property directly will give a `KeyError` instead of the intended
`ImproperlyConfigured` error.
Worse, if you try to access a non-default db, `ensure_defaults` will
catch that `KeyError` but misinterpret it as being for the non-default
db name (which does in fact exist in the dict).
This change moves the explicit check before the attempt to use the key,
so that no `KeyError` is ever raised for `DEFAULT_DB_ALIAS`. It adds
a test for this case, and also adds a test for the case where the
default db is explicitly set to an empty dict.
--
Ticket URL: <https://code.djangoproject.com/ticket/30071>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
* owner: nobody => Benjy Weinberger
* status: new => assigned
* component: Uncategorized => Database layer (models, ORM)
Comment:
See https://github.com/django/django/pull/10813
--
Ticket URL: <https://code.djangoproject.com/ticket/30071#comment:1>
Comment (by Benjy Weinberger):
Ticket branch here: https://github.com/benjyw/django/tree/ticket_30071
--
Ticket URL: <https://code.djangoproject.com/ticket/30071#comment:2>
Old description:
> In `ConnectionHandler`, the explicit check for the `DEFAULT_DB_ALIAS`
> key in the databases dict comes only after an attempt to lookup that key.
>
> If you have at least one non-default db, but no default db, no dummy
> default will be created for you, and the `DEFAULT_DB_ALIAS` key will
> not be present. Under these circumstances, referencing the `databases`
> property directly will give a `KeyError` instead of the intended
> `ImproperlyConfigured` error.
>
> Worse, if you try to access a non-default db, `ensure_defaults` will
> catch that `KeyError` but misinterpret it as being for the non-default
> db name (which does in fact exist in the dict).
>
> This change moves the explicit check before the attempt to use the key,
> so that no `KeyError` is ever raised for `DEFAULT_DB_ALIAS`. It adds
> a test for this case, and also adds a test for the case where the
> default db is explicitly set to an empty dict.
New description:
In `ConnectionHandler`, the explicit check for the `DEFAULT_DB_ALIAS`
key in the databases dict comes only after an attempt to lookup that key.
If you have at least one non-default db, but no default db, no dummy
default will be created for you, and the `DEFAULT_DB_ALIAS` key will
not be present. Under these circumstances, referencing the `databases`
property directly will give a `KeyError` instead of the intended
`ImproperlyConfigured` error.
Worse, if you try to access a non-default db, `ensure_defaults` will
catch that `KeyError` but misinterpret it as being for the non-default
db name (which does in fact exist in the dict).
--
--
Ticket URL: <https://code.djangoproject.com/ticket/30071#comment:3>
* type: Uncategorized => Bug
* stage: Unreviewed => Accepted
--
Ticket URL: <https://code.djangoproject.com/ticket/30071#comment:4>
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"222caab68a2a7345043d0c50161203cb2cfe70eb" 222caab6]:
{{{
#!CommitTicketReference repository=""
revision="222caab68a2a7345043d0c50161203cb2cfe70eb"
Fixed #30071 -- Fixed error message when a 'default' database isn't
provided.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/30071#comment:5>