CODEWITHSUNDEEP
djangodjango-modelsdjango-formsdjango-templatesdjango-admin
defoe
defoe

Reputation: 369

How to execute custom SQL query when deleting a model item in Django?

I want to execute an SQL query, when an item gets deleted in the admin interface. In models.py I do this:

from django.db import connection

class LList(models.Model):
    item = models.ForeignKey(Item, models.DO_NOTHING)

    def delete(self, *args, **kwargs):
        cursor = connection.cursor()
        cursor.execute('DELETE FROM some_table where item = %d', [self.item.id])

When I turn debugging on I see all the queries executed. It seems the DELETE FROM query is not executed, I only see

(0.000) DELETE FROM `llist` WHERE `llist`.`id` IN (27); args=(27,)

Why is the other DELETE FROM query not executed? How can I fix that?

Upvotes: 0

Views: 758

Answers (1)

HabibUllah Khan
HabibUllah Khan

Reputation: 111

You are overriding the delete function the wrong way,

def delete(self, using=None, keep_parents=False):
    with connection.cursor() as cursor:
        cursor.execute('''DELETE FROM some_table where item = %d''', [self.item.id])

    super(LList, self).delete(using, keep_parents)

But I believe the better way would be to do it using signals, you should create a pre_delete signal.

Upvotes: 1

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