我看到一些有關(guān)此錯(cuò)誤的主題，但找不到答案。這是我的錯(cuò)誤：django.db.utils.IntegrityError: NOT NULL constraint failed: domain_analyse_practice.header_id我真的不明白為什么會(huì)發(fā)生此錯(cuò)誤。我的models.py：class Header(models.Model):    name = models.CharField(max_length=40, null=False)    description = models.CharField(max_length=500, null=False)class Practice(models.Model):    nature = models.CharField(max_length=10, null=False)    value = models.CharField(max_length=300, null=False)    further = models.CharField(max_length=50, null=True, blank=True)    header = models.ForeignKey(Header, on_delete=models.CASCADE)    def value_cleaner(self):        self.value = self.value.replace("‘","'").replace("’", "'")    def __init__(self, *args, **kwargs):        super(Practice, self).__init__()        self.value_cleaner()這是我的init_db.py腳本，它負(fù)責(zé)填充數(shù)據(jù)庫：def init_practice_db(filename):with open('config/' + filename, newline='') as csv_file:    reader = csv.reader(csv_file, delimiter=',', quotechar='|')    i = 0    for row in reader:        if i != 0:            # Not the header row            header_name = row[0]            # Select the header in database with header name            header = Header.objects.get(name=header_name)            further = None            nature = row[1].rstrip()            value = row[2].rstrip()            if row[3] != "None":                further = further            Practice.objects.create(nature=nature, value=value, further=further, header=header)        i += 1如果缺少某些信息，請告訴我:)謝謝您的回答。