Django How to UPDATE ... RETURNING

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.

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# 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:

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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.