python - 如何在 Django 中为字典批量创建和保存对象

Question

我想为我的模型批量创建对象。我的模型是

class Fees(models.Model):
    city = models.CharField(max_length=200, blank=True)
    contact = models.CharField(max_length=200, blank=True)
    class = models.CharField(max_length=200, blank=True)
    veg = models.BooleanField(default=False)
    rollno = models.CharField(max_length=200, blank=True)

我的字典值是 -

response = {
    'A101': {
        'VEG': True,
        'CONTACT': '12345',
        'CLASS': 'SIX',
        'ROLLNO': 'A101',
        'CITY': 'CHANDI',
    },
    'A102': {
        'VEG': True,
        'CONTACT': '54321',
        'CLASS': 'SEVEN',
        'ROLLNO': 'A102',
        'CITY': 'GANGTOK',
    },
}

目前我正在做如下 -

def create_obj(response):
    for key, value in response.items():
        fee_obj, _ = Fees.objects.get_or_create(
            rollno=key, defaults={
                **change_value
            })
        yield fee_obj

那么我怎样才能批量创建对象。任何帮助将不胜感激。

Answer 1

您可以按照以下几行进行尝试，这只会产生 2 次数据库命中:

def create_obj(response):
    # 1st db query: existing fees instances form response
    existing = Fees.objects.filter(rollno__in=response.keys())

    keys = set(f.rollno for f in existing)

    # 2nd db query: bulk create non-existing
    new = Fees.objects.bulk_create([
         Fees(**{ke.lower(): va for ke, va in value.items()})
         for key, value in response.items() if key not in keys
    ])

    yield from existing
    yield from new