id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
36911	Raise an error when GeneratedField provided to fields argument of bulk_update()	jaffar Khan		"Currently, bulk_update() does not validate if the fields provided in the fields=[...] argument are GeneratedField instances.

Model:
{{{
    class Product(models.Model):
        price = models.IntegerField()
        quantity = models.IntegerField()
        total = models.GeneratedField(
            expression=models.F(""price"") * models.F(""quantity""),
            output_field=models.IntegerField(),
            db_persist=True,
        )
}}}

test function:
{{{
def run_test():
    
    # Create product
    p = Product.objects.create(price=10, quantity=2)

    p.total = 9999
    
    try:
        Product.objects.bulk_update([p], fields=[""total""])        
        print(""silent failure"")
            
    except Exception as e:
        print(f""CRASH: {e}"")
}}}
output:
**silent failure**

If a developer accidentally includes a **GeneratedField** in **bulk_update()**, Django attempts to include it in the SQL UPDATE statement.
On SQLite, this results in a silent failure (no error is raised, but the value is obviously not updated as it is generated).
On strict databases (like PostgreSQL), this likely results in an OperationalError.

Django should raise a FieldError immediately when **bulk_update()** is called with a **GeneratedField**, similar to how it handles other read-only fields or invalid field names."	Bug	closed	Database layer (models, ORM)	dev	Normal	wontfix	bulk_update GeneratedField	jaffar Khan	Unreviewed	0	0	0	0	0	0