I saw in the documentation than since Doctrine 2.4 we could join without associations, using fields.
However I tried it and it generates invalid SQL (I use master). Here is an example:
Generates the following SQL:
As you can see, instead of "INNER JOIN ... ON ..." we have "INNER JOIN ... AND ..." which is invalid.
I can't say if it's a regression of 2.5, or already in 2.4. I can't test my project with 2.4 because I used embedded objects.