On Thu, Jun 30, 2011 at 5:19 PM, peroksid <[email protected]> wrote:
>
> I need to have for the "ON" expression slighlty more complex
> expression, something like
> "left_table.left_column=right_table.right_column AND
> right_table.another_column=42". Method join() obviously can not be
> used for this purpose because it tuple defining join connection
> consists off 4 elements.
> I suspect there is no way to create such a double join condition at
> all, event without constant involved instead of column.
Maybe you can use F objects to create the correct filters? It would be
something like:
object_list =
ObjectModel.filter(sometable__leftcolumn=F('right_table__right_column'))
and then you can use Q objects to combine two of them:
q1 = Q(sometable__leftcolumn=F('right_table__right_column'))
q2 = Q(right_table__another_column=42)
object_list = ObjectModel.filter(q1 & q2)
more info at:
https://docs.djangoproject.com/en/dev/topics/db/queries/#filters-can-reference-fields-on-the-model
https://docs.djangoproject.com/en/dev/topics/db/queries/#complex-lookups-with-q-objects
--
Gianluca Sforna
http://morefedora.blogspot.com
http://identi.ca/giallu - http://twitter.com/giallu
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