How do I use a django join to select customer_name for every id that is returned in a result from a summary table?

I've been looking into django joins, and I can see how I can select related fields with .select_related but I can't seem to get it to work how I want. I basically have summary tables that are linked to the customers table with customer_id FK's, I want to select the customer name from the customers field for every value returned for each of the summaries.

I included pseudo code to show what im trying to do.

    sql would be = ''' select a.customer_name, b.vm_name, b.vm_cpu, b.vm_mem from customers a, vms b where a.customer_id = b.customer_id'''

how do I do that with django. That way when I loop through the returned values

    for value in sql:
        list.append(value.1, value.2, value.3)

that way I can associate and output the customer_name with each field.

Heres what I'm trying to do:

     compute_usages = ComputeUsages.objects.filter(customer_id = customer_id).filter(load_date = datetime(year, day, selected_month)).select_related()
     for row in compute_usages:
            if not 'Microsoft' in row.guest_os:
               compute_return_query_linux.append((row.customers.customer_name, row.vm_name, row.vm_id, row.core_hours, row.ram_hours, row.guest_os, row.provisioned_cores, row.provisioned_ram, row.datetime, row.load_date))
            else:
               compute_return_query_microsoft.append((row.customers.customer_name, row.vm_name, row.vm_id, row.core_hours, row.ram_hours, row.guest_os, row.provisioned_cores, row.provisioned_ram, row.datetime, row.load_date))
   

obviously that doesn't work.

basically that one is for specific customers, but there is a case where company employees with admin rights can query the entire database for all customers and create a usage report so I need to associate customer_names with the query.




Any ideas on how to do this with django?


Models:

    class Customers(models.Model):
        customer_id = models.BigIntegerField(primary_key=True, editable=False)
        customer_name = models.CharField(max_length=100)
        inactive = models.CharField(max_length=1)
        datetime = models.DateTimeField()
        class Meta:
            managed = True
            db_table = 'customers'
       
        def __unicode__(self):  # Python 3: def __str__(self):
          return self.customer_name
       
        def clean(self):
          if self.inactive != 'Y' and self.inactive != 'N':
             raise ValidationError('Please enter a Y or N')
   
    class ComputeUsages(models.Model):
        compute_usage_id = models.AutoField(primary_key=True, editable=False)
        customer = models.ForeignKey(Customers)
        vm_name = models.CharField(max_length=4000)
        vm_id = models.BigIntegerField()
        core_hours = models.DecimalField(max_digits=15, decimal_places=2)
        ram_hours = models.DecimalField(max_digits=15, decimal_places=2)
        guest_os = models.CharField(max_length=100)
        provisioned_cores = models.BigIntegerField()
        provisioned_ram = models.BigIntegerField()
        load_date = models.DateField()
        datetime = models.DateTimeField()
   
        class Meta:
            managed = True
            db_table = 'compute_usages'
       
        def __unicode__(self):  # Python 3: def __str__(self):
          return self.vm_name

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