具有 Null 值的 django bulk_create

Question

models.py

class control(models.Model):
    amount = models.IntegerField()
    driver = models.ForeignKey(driver, on_delete=models.CASCADE, null=True, blank=True)

views.py

controlValues = [
    (1,1,1),
    (2,8,None)
]
control.objects.bulk_create([
    control(
        id = i[0],
        amount = i[1],
        driver = driver(id = i[2])
    ) for i in controlValues], ignore_conflicts=True
)

我收到错误： bulk_create() 禁止，以防止因未保存相关对象而导致数据丢失'driver'。如何为驱动程序设置 Null？我正在使用 mysql.

Answer 1

如果值为 None，您不应使用该对象构建 driver 模型，而应使用：

control.objects.bulk_create([
    control(
        id=id,
        amount=amount,
        driver=driver(id=dr_id) <strong>if dr_id is not None else None</strong>
    ) for id, amount, dr_id in controlValues],
    ignore_conflicts=True
)

或更简单：

control.objects.bulk_create([
    control(
        id=id,
        amount=amount,
        <b>driver_id=dr_id</b>
    ) for id, amount, dr_id in controlValues],
    ignore_conflicts=True
)

Note: Models in Django are written in PascalCase, not snake_case, so you might want to rename the model from ~~driver~~ to Driver.

具有 Null 值的 django bulk_create

django bulk_create with Null value

django

django-views