Raw SQL query in Django

Question

Is there any nothing wrong with this raw query?

Worker.objects.raw('Delete from customer_worker Where customer_ptr_id= %s', [customer.id])

Customer id returns a string, but it seems like nothing happen, the object is still there after the execution.

The object Worker is a child object from Customer , I want to remain the customer, but delete the Worker object.

Here are the Customer and Worker models:

class Customer(User):                                                    
    slug=models.SlugField(unique=True)
    description=models.TextField(null=True)
    phone=models.IntegerField(null=True)
    isWorker=models.BooleanField()

    def save(self,*args,**kwargs):                                        
        self.slug=slugify(self.username)                                          
        super(Customer,self).save(*args, **kwargs)                             

    def __unicode__(self):
        return self.username


class Worker(Customer):
    comment=models.ForeignKey(Comment, null=True)
    keyword=models.ManyToManyField('job.JobGenre', null=True)

    def __unicode__(self):
        return self.username

Answer 1

You can delete your record(s) directly via connection.cursor() ( docs ):

from django.db import connection

cursor = connection.cursor()
cursor.execute('DELETE FROM costumer_worker WHERE costumer_ptr_id = %s', [costumer.id])
connection.commit()

But, the thing you're trying to do looks too simple to write SQL directly, use django ORM instead.

Answer 2

You may be missing comitting the transcation. Based on your settings, you may need to add : transaction.commit_unless_managed() in django 1.4 ( not needed in django 1.5, since default settings are different)

Answer 3

use this line:

from django.db import connection, transaction
cursor = connection.cursor()
with transaction.commit_on_success():
   cursor.execute('DELETE FROM costumer_worker WHERE costumer_ptr_id = %s', [costumer.id])
   connection.commit()