django 数据库交互2

打开django shell

python manage.py shell

输入命令

>>> from myapp import *
>>> MySite.objects.all()

插入一条命令

m=Mysite(title='django',num=2)
m.save()

然后再查询

>>> m=Mysite(title='django',num=2)
>>> m.save()
>>> Mysite.objects.all()
[<Mysite: Mysite object>]
>>> m=Mysite.objects.all()
>>> m[0]
<Mysite: Mysite object>
>>> m[0].title

过滤

>>> m=Mysite.objects.get(num=2)
>>> m.title

排序

>>> m=Mysite(title='lala',num='3')
>>> m.save()
>>> m=Mysite(title='dongshen',num='1')
>>> m.save()
>>> m=Mysite(title="niusen",num='5')
>>> m.save()
>>> m=Mysite.objects.all().order_by("num")
>>> m[0].num

//倒序排列
>>> m=Mysite.objects.all().order_by("-num")
>>> m[0].num

也可以修改models，这样每次都可以按照num排序

from django.db import models

# Create your models here.
class Mysite(models.Model):
    title=models.CharField(max_length=100)
    url=models.URLField()
    author=models.CharField(max_length=100)
    num=models.IntegerField(max_length=10)

    class Meta:
        ordering=['num']

更新

>>> x=m[0]
>>> x
<Mysite: Mysite object>
>>> x.title
u'niusen'
>>> x.title="loongshen"
>>> x.save()
>>> x.title
'loongshen'

删除

>>> x.delete()
>>> Mysite.objects.get(num=0)

限制只取前几条数据

Mysite.objects.all()[0:1]