Can Django models use MySQL functions?

Question

Is there a way to force Django models to pass a field to a MySQL function every time the model data is read or loaded? To clarify what I mean in SQL, I want the Django model to

Answer 1

It's definitely hackish, but it seems Django won't let you do it any other way at the moment. It's also worth noting that to_python will be called every time you change the value in python in addition to when it is first loaded.

from django.db import connection, models
import re

class EncryptedField(models.TextField):
    __metaclass__ = models.SubfieldBase

    def to_python(self, value):
        if not re.match('^*some pattern here*$', value):
            cursor = connection.cursor()
            cursor.execute('SELECT AES_DECRYPT(%s, %s)', [value, settings.SECRET_KEY])
            return cursor.fetchone()[0]
        return value

    def get_db_prep_value(self, value):
        cursor = connection.cursor()
        cursor.execute('SELECT AES_ENCRYPT(%s, %s)', [value, settings.SECRET_KEY])
        return cursor.fetchone()[0]


class Encrypt(models.Model):
    encrypted = EncryptedField(max_length = 32)