Bug in JsonField with null=False

[Ronaldo Campos]

I recently updated my project's Django to version 3.1.5 and removed its jsonfield dependency to use the new JSONField released with Django 3.1. However i'm experiencing quite a strange bug.

I was experimenting creating a new JSONField with different options and here is what i found:

Suppose I have a migration like this

        migrations.AlterField(
            model_name='awsuserschedule',
            name='selected_ids',
            field=common.fields.JSONField(encoder=common.encoders.JSONEncoder, null=True),
        ),
        migrations.AlterField(
            model_name='awsuserschedule',
            name='tags',
            field=common.fields.JSONField(default=list, encoder=common.encoders.JSONEncoder),
        ),
        migrations.AlterField(
            model_name='userscheduleslog',
            name='instance_ids',
            field=common.fields.JSONField(default=list, encoder=common.encoders.JSONEncoder, null=False),
        ),

When i run sqlmigrate to analyze this migration i get:

-- Alter field selected_ids on awsuserschedule
--
ALTER TABLE `aws_user_schedules` MODIFY `selected_ids` json NULL;
--
-- Alter field tags on awsuserschedule
--
--
-- Alter field instance_ids on userscheduleslog
--

So you see that when null is not passed, or null=False, there is no sql query created at all. I'm using MySQL 5.7.22. Am i doing something wrong?

Thanks

[Mariusz Felisiak]

Thanks for this report, however there is not enough details to understand or reproduce your issue. What kind of JSONField did you use before? What was the models' state before this operations? Can you provide a sample project?

[Ronaldo Campos]

I was using the jsonfield library. But, never mind i think i figured out what i was doing wrong. It was an issue on the previous migration states that was causing sqlmigrate to avoid doing anything. Feel free to close the bug report.

[Mariusz Felisiak]

Thanks for the feedback.