django 的网站创建步骤（四）Shell的使用

1.执行命令 ： python manage.py shell 打开一个控制台

2. 执行如下命令序列进行,并查看结果

>>>from polls.models import Choice,Question

>>>Question.objects.all()

>>>from django.utils import timezone

>>>q = Question(question_text =" What 's new ?",pub_date=timezone.now())

>>>q.save()

>>>q.id

>>>q.question_text

>>>q.pub_date

>>>q.question_text = "What's up?"

>>>q.save()

>>>Question.objects.all()

3.修改数据模型：

再执行shell命令，并查看结果：

>>> from polls.models import Choice,Quesiton

>>>Question.objects.all()

>>>Question.objects.filter(id=1) #相当于where id=1 

>>>Question.objects.filter(question_text__startswith='What')

>>>from django.utils import timezone

>>>current_year = timezone.now().year

>>>Question.objects.get(pub_date__year=current_year)

>>>Question.objects.get(id=2)

这个会报错是正常的，错误如下：

Tranceback (most recent call last):

...

DoesNotExist :Question matching query does not exist.

>>>Question.objects.get(pk=1)  #pk其实就是id，pk的意思就是关键字

>>>q = Question.objects.get(pk=1)

>>>q.was_published_recently()  #返回结果是True

>>>q = Question.objects.get(pk=1)

>>> q.choice_set.all() #取关联的所有数据

>>>q.choice_set.create(choice_text='Not much',votes=0)

>>>q.choice_set.create(choice_text='The sky',votes=0)

>>>c=q.choice_set.create(choice_text='Just hacking again',voites=0)

>>>c.question

>>>q.choice_set.all()

>>>q.choice_set.count() #返回3

>>>Choice.objects.filter(question__pub_date__year =current_year)

>>>c=q.choice_set.filter(choice_text__startswith='Just hacking')

>>>c.delete() #删除