Django ForeignKey,null = True,内连接和左外连接
假设我有两个Django模型人和公司如下： class Company(models.Model): name = models.CharField()class Person(models.Model): last_name = models.CharField(blank=True) first_name = models.CharField() compa
假设我有两个Django模型人和公司如下： class Company(models.Model): name = models.CharField()class Person(models.Model): last_name = models.CharField(blank=True) first_name = models.CharField() compa