django进阶
django ORM操作 models.py from django.db import models # Create your models here. class Book(models.Model): name = models.CharField(max_length=128) price = models.PositiveSmallIntegerField(null=True)#正数,null=True不是必填 authors = models.ManyToManyField('Author') publisher = models.ForeignKey('Publisher') pub_date = models.DateField() # memo = models.CharField(null=True,max_length=64)数据库新增字段的时候,需要加上null=True #为了在查询时显示对象的名字 def __str__(self): return self.name class Author(models.Model): name = models.CharField(max_length=32) email = models.EmailField(unique=True) def __str__(self): return self.name