In Django, the
UPDATE ... RETURNING functionality is not directly supported out of the box. The
UPDATE ... RETURNING statement is specific to certain databases (e.g., PostgreSQL), and it allows you to update rows in a table and return the updated values in a single query.
However, in Django, you can achieve a similar effect by performing two separate queries: one for the update and another for fetching the updated data. Here's how you can do it:
Let's assume you have a model called
MyModel with a field named
some_field that you want to update and return its new value.
# models.py from django.db import models class MyModel(models.Model): some_field = models.CharField(max_length=100)
In your view or any other part of your Django code, you can perform the update and retrieve the updated data as follows:
from django.db import transaction from myapp.models import MyModel def update_and_return_value(pk, new_value): with transaction.atomic(): # Update the record MyModel.objects.filter(pk=pk).update(some_field=new_value) # Retrieve the updated data updated_record = MyModel.objects.get(pk=pk) return updated_record.some_field
In this example, we first use
update() to update the
some_field value for the specific record identified by
pk. Then, we use
get() to fetch the updated data with the new value of
some_field. The use of
transaction.atomic() ensures that both the update and retrieval operations are executed within a single database transaction.
While this approach is not as concise as the
UPDATE ... RETURNING statement, it achieves a similar result by updating the data and fetching the updated value in a single database transaction.
Keep in mind that the exact implementation might vary depending on your specific use case and database backend. Also, note that not all databases support the
RETURNING clause in their
UPDATE statements, so the two-query approach is a more generic solution that works with various database backends supported by Django.