如何在Django中不同模型的任何兩個字段之間建立OneToOne關系？

Question

class HmsMedicine(models.Model):
    id = models.IntegerField(primary_key=True)
    medicine_name = models.CharField(max_length=100)
    price = models.IntegerField(max_length=6)

class HmsBilling(models.Model):
    id = models.IntegerField(primary_key=True)
    regid = models.ForeignKey(HmsPatient, db_column='regid')
    medicine = models.ForeignKey(HmsMedicine, db_column='medicine')
    quantity = models.IntegerField()
    rate = models.IntegerField()

我想在rate字段中輸入price字段的值。

Answer 1

class HmsBilling(models.Model):
    id = models.IntegerField(primary_key=True)
    regid = models.ForeignKey(HmsPatient, db_column='regid')
    medicine = models.ForeignKey(HmsMedicine, db_column='medicine')
    quantity = models.IntegerField()
    rate = models.ForeignKey(HmsMedicine, db_column='price')

hms = HmsBilling.objects.select_related().get(id=5)
hms.rate

這將為您提供ID = 5的結算價格（有關選擇相關內容，請參閱此鏈接以獲取參考）

更好：

class HmsBilling(models.Model):
    id = models.IntegerField(primary_key=True)
    medicine = models.ForeignKey(HmsMedicine)
    quantity = models.IntegerField()

hms = HmsBilling.objects.select_related().get(id=5)
hms.medicine.price