How to create complex Left JOIN in Django

[Shoaib Ijaz]

I am trying to create multi Model Left join using django

Here is my model

class LookupTiming(models.Model):
    day = models.CharField(max_length=7)
    time_1 = models.TimeField()
    time_2 = models.TimeField()

    class Meta:
        db_table = u'lookup_timing'

class Streets(models.Model):
    name = models.CharField(max_length=50)
    point = models.GeometryField(null=True, blank=True)
    objects = models.GeoManager()

    class Meta:
        db_table = u'streets'

    def __unicode__(self):
        return '%s' % self.name


class StreetTimings(models.Model):
    street= models.ForeignKey(Streets)
    lookuptiming = models.ForeignKey(LookupTiming)
    class Meta:
        db_table = u'street_timings'

This is query that i have created

Streets.objects.filter(streettimings_isnull=True).filter(streettimings_lookuptiming__isnull=True).values('id')

This is sql output of above query

SELECT "streets"."id" FROM "streets"
LEFT OUTER JOIN "street_timings" ON ( "streets"."id" = "street_timings"."street_id" ) 
LEFT OUTER JOIN "street_timings" T3 ON ( "streets"."id" = T3."street_id" )
WHERE ("street_timings"."id" IS NULL AND T3."lookuptiming" IS NULL)

But i want following query

select st.id from streets st
LEFT JOIN street_timings timing on timing.street_id = st.id 
LEFT JOIN lookup_timing lt on lt.id = timing.lookuptiming_id 

So problem is that, the django query total ignore lookuptiming Model. I want to create following joins

Streets(id) = StreetTimings (street_id)

LookupTiming (id) = StreetTimings (lookuptiming_id)

How can i create left join for multiple models?

Thank you