django增删改查

1. 增

class Role(models.Model):
  title = models.CharField(verbose_name="角色", max_length=32)
  od = models.IntegerField(verbose_name="排序", default=0)
  
  def __str__(self):
    return "{}-{}-{}".format(self.id, self.title, self.od)

方法一：
obj1 = models.Role.objects.create(title="管理员", od=1)

obj1 = models.Role.objects.create(**{"title":"管理员", "od":1})   # 字典传值


方法二：
obj = models.Role(title="管理员", od=1)   # 此时数据只在内存中
obj.od = 2                               # 还可以修改
obj.save()                                # 写入到数据库

2. 删除

models.Role.objects.filter(id=1).delete()
models.Role.objects.filter(title="管理员").delete()

3. 修改

models.Role.objects.all().update(od=99)
models.Role.objects.filter(id=1).update(od=99, title="管理员")
models.Role.objects.filter(id=1).update(**{"title":"管理员", "od":1})   # 字典传值

4. 查询

v1 = models.Role.objects.all()
for obj in v1:
  print(obj.id, )


v2 = models.Role.objects.filter(od=99, id=7)     # where id=7
for obj in v2:
  print(obj.id, )

v3 = models.Role.objects.filter(od__gt=2)     # where od>2
print(v3.query)   # 查看sql语句
v4 = models.Role.objects.filter(od__gte=2)     # where od>=2

v3 = models.Role.objects.filter(od__lt=2)     # where od<2
v4 = models.Role.objects.filter(od__lte=2)     # where od<=2

v3 = models.Role.objects.filter(id__in=[2,4,6])     # where id=2 and id=4 and id=6

v3 = models.Role.objects.filter(title__contains="管") 
v3 = models.Role.objects.filter(title__startswith="管") 
v3 = models.Role.objects.filter(title__isnull=True) 

v3 = models.Role.objects.exclude(id=99)   # id不等于99