You are trying to add a non-nullable field 'birthday' to scustomer without a default; we can't do that (the database needs something to populate existing rows).

这个错误是因为你正在试图向 scustomer 模型添加一个非空字段 'birthday'，但是你没有提供默认值，因此无法应用该更改。这个错误提示告诉你需要提供一个默认值，以便在数据库中为现有行填充数据。你可以通过提供一个默认值或者允许该字段为空来解决这个问题。如果你不想在数据库中为现有行提供默认值，你可以在添加字段时指定一个空值，然后手动更新每一行。

相关问题

You are trying to add a non-nullable field 'Number' to author without a default; we can't do that (the database needs something to populate existing rows). Please select a fix: 1) Provide a one-off default now (will be set on all existing rows with a null value for this column) 2) Quit, and let me add a default in models.py

It seems like you are facing a database migration issue in Django. In this case, you have added a non-nullable field 'Number' to the 'author' model without a default value, and there are existing rows with null values for this column.

To solve this issue, you have two options:

1. Provide a one-off default now: You can provide a default value for the 'Number' field that will be set on all existing rows with a null value for this column. You can do this by running the following command in your Django project directory:

   python manage.py makemigrations --empty yourappname

This will create an empty migration file for your app. Then add the following code to the `operations` list in the `migrations.RunPython` method:

   from django.db import migrations

   def set_default_value(apps, schema_editor):
       Author = apps.get_model('yourappname', 'Author')
       Author.objects.filter(Number=None).update(Number=0)

   class Migration(migrations.Migration):

       dependencies = [
           ('yourappname', 'previous_migration'),
       ]

       operations = [
           migrations.RunPython(set_default_value),
       ]

Replace 'yourappname' and 'previous_migration' with your actual app name and the previous migration name respectively. Then run the following command:

   python manage.py migrate

This will apply the migration and set the default value for the 'Number' field on all existing rows with null values.

2. Quit, and let me add a default in models.py: If you don't want to provide a default value for the 'Number' field, you can quit the migration process and add a default value in the 'author' model in your models.py file. You can do this by adding the following code to your model:

   class Author(models.Model):
       name = models.CharField(max_length=100)
       # Add default value for Number field
       Number = models.IntegerField(default=0)

Then run the following command to create a new migration:

   python manage.py makemigrations

This will create a new migration file with the default value for the 'Number' field. Then run the following command to apply the migration:

   python manage.py migrate

This will apply the migration and add the default value for the 'Number' field in the 'author' model.

you're trying to animate a non-existing property angle of your QObject

As an AI language model, I do not have any QObject or animation capabilities, but I can offer some general guidance.

If you are trying to animate a property that does not exist in your QObject, you will need to create that property first. You can do this by using the Q_PROPERTY macro in your QObject's header file to define the new property.

For example, if you wanted to create a new angle property for a custom widget, you could add the following code to the header file:

class MyWidget : public QWidget
{
    Q_OBJECT
    Q_PROPERTY(qreal angle READ angle WRITE setAngle)

public:
    MyWidget(QWidget *parent = nullptr);
    qreal angle() const;
    void setAngle(qreal angle);

private:
    qreal m_angle;
};

This code creates a new property called "angle" that can be read and written using the accessor functions angle() and setAngle().

Once you have created the property, you can then animate it using the QPropertyAnimation class or other animation frameworks.