migrations.py 文件源码

def add_field(field, filters: List[str]):
    """Adds the specified field to a model.

    Arguments:
        field:
            The field to add to a model.

        filters:
            List of strings to filter
            SQL statements on.
    """

    model = define_fake_model()
    project = migrations.state.ProjectState.from_apps(apps)

    with connection.schema_editor() as schema_editor:
        execute_migration(schema_editor, [
            migrations.CreateModel(
                model.__name__,
                fields=[]
            )
        ], project)

    with filtered_schema_editor(*filters) as (schema_editor, calls):
        execute_migration(schema_editor, [
            migrations.AddField(
                model.__name__,
                'title',
                field
            )
        ], project)

    yield calls