gistfile1.txt

import django.db
import collections

all_models = django.db.models.get_models()

def find_deps(models):
    """ return a dict of {model : [all dependent models] """
    deps = collections.defaultdict(set)
    name_to_model = {}
    for model in models:
        table = model._meta.db_table
        name_to_model[table] = model
        others = model._meta.get_all_related_objects()
        for other in others:
            oth_table = other.model._meta.db_table
            name_to_model[oth_table] = other.model
            deps[table].add(oth_table)
    old_count = 0
    new_count = sum(len(l) for l in deps.values())
    while old_count != new_count:
        old_count = new_count
        for tab, others in deps.items():
            new_others = set(others)
            for item in others:
                new_others |= deps[item]
            deps[tab] = new_others
        new_count = sum(len(l) for l in deps.values())

    out = {}
    for k, v in deps.items():
        out[name_to_model[k]] = map(name_to_model.__getitem__, v)
    return out

def dependency_names():
    model_to_deps = find_deps(all_models)
    text_deps = {}
    for k, v in model_to_deps.items():
        text_deps[k._meta.db_table] = [m._meta.db_table for m in v]
    return text_deps

def print_deps(deps):
    print 'table => list of tables in the cascade'
    print '-' * 80
    for tab, others in sorted(deps.items()):
        if others:
            print '%s => %s' % (tab, ', '.join(sorted(list(others))))

if __name__ == '__main__':
    print_deps(dependency_names())