django-form

class Report(models.Model):
    client = models.ForeignKey(Client, on_delete=models.CASCADE, null=True, blank=True)
    result_doc = models.FileField(upload_to="lab_result_doc/%Y/%m/%d", null=True, blank=True)
    date_of_loss = models.DateTimeField(null=True, blank=True)
    date_of_inspection = models.DateTimeField(null=True, blank=True)
    report_date = models.DateTimeField(null=True, blank=True)
    inspector = models.ForeignKey(Inspector, on_delete=models.CASCADE, null=True, blank=True)
    license = models.CharField(max_length=100, null=True, blank=True)
    observations = models.CharField(max_length=100, choices=OBSERVATION_CHOICES, blank=True, null=True)
    report_sample = models.ManyToManyField('ReportSample', verbose_name='samples')


class ReportSample(models.Model):
    serial = models.CharField(max_length=200)
    location = models.CharField(max_length=200)
    results = models.CharField(max_length=200, null=True, blank=True)
    analysis = models.ForeignKey(SampleType, on_delete=models.CASCADE)
    upload_picture = models.FileField(upload_to="sample/%Y/%m/%d")
    picture_title = models.CharField(max_length=200