How to join non-relational models in Django 1.3 on 2 fields -

i've got 2 existing models need join non-relational (no foreign keys). these written other developers cannot modified me.

here's quick description of them:

model process

• field filename
• field path
• field somethingelse
• field bar

model service

• field filename
• field path
• field servicename
• field foo

i need join instances of these 2 models on filename , path columns. i've got existing filters have apply each of them before join occurs.

example:

a = process.objects.filter(somethingelse=231)

b = service.objects.filter(foo='abc')

result = a.filter(filename=b.filename,path=b.path)

this sucks, best bet iterate models of 1 type, , issue queries joined models other type.

the other alternative run raw sql query perform these joins, , retrieve ids each model object, , retrieve each joined pair based on that. more efficient @ run time, need manually maintained if schema evolves.