django数据库基本操作-增删改查（tip）-基本

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1、插入数据

Python代码

1. >>> from books.models import Publisher  
2. >>> p1 = Publisher(name='Apress', address='2855 Telegraph Avenue',  
3. ...     city='Berkeley', state_province='CA', country='U.S.A.',  
4. ...     website='http://www.apress.com/')  
5. >>> p1.save()  

>>> from books.models import Publisher>>> p1 = Publisher(name='Apress', address='2855 Telegraph Avenue',... city='Berkeley', state_province='CA', country='U.S.A.',... website='http://www.apress.com/')>>> p1.save()

2、查询

Python代码

1. >>> Publisher.objects.all()  
2. [<Publisher: Apress>, <Publisher: O'Reilly>]  

>>> Publisher.objects.all()[<Publisher: Apress>, <Publisher: O'Reilly>]

获取单个对象：

Python代码

1. >>> Publisher.objects.get(name="Apress")  
2. <Publisher: Apress>  

>>> Publisher.objects.get(name="Apress")<Publisher: Apress>如果结果是多个对象或者没有返回结果则会抛出异常

3、条件

筛选：

Python代码

1. >>> Publisher.objects.filter(name='Apress')  
2. [<Publisher: Apress>]  

>>> Publisher.objects.filter(name='Apress')[<Publisher: Apress>]

Python代码

1. >>> Publisher.objects.filter(name__contains="press")  
2. [<Publisher: Apress>]  

>>> Publisher.objects.filter(name__contains="press")[<Publisher: Apress>]__contains部分会被Django翻译成LIKE语句

排序：

Python代码

1. >>> Publisher.objects.order_by("name")  
2. [<Publisher: Apress>, <Publisher: O'Reilly>]  

>>> Publisher.objects.order_by("name")[<Publisher: Apress>, <Publisher: O'Reilly>]

相当于 order by name asc

Python代码

1. >>> Publisher.objects.order_by("-name")  

>>> Publisher.objects.order_by("-name")加个负号相当于 order by name desc

限制返回数据：

Python代码

1. >>> Publisher.objects.order_by('name')[0]  
2. <Publisher: Apress>  

>>> Publisher.objects.order_by('name')[0]<Publisher: Apress>相当于 limit 1

Python代码

1. >>> Publisher.objects.order_by('name')[0:2]  

>>> Publisher.objects.order_by('name')[0:2]相当于 OFFSET 0 LIMIT 2

4、更新

Python代码

1. >>> Publisher.objects.filter(id=52).update(name='Apress Publishing')  

>>> Publisher.objects.filter(id=52).update(name='Apress Publishing')

Python代码

1. >>> p = Publisher.objects.get(name='Apress') #先查询  
2. >>> p.name = 'Apress Publishing' #更新  
3. >>> p.save()  #保存  

>>> p = Publisher.objects.get(name='Apress') #先查询>>> p.name = 'Apress Publishing' #更新>>> p.save() #保存
5、删除

Python代码

1. >>> p = Publisher.objects.get(name="O'Reilly")  
2. >>> p.delete()  

>>> p = Publisher.objects.get(name="O'Reilly")>>> p.delete()

Python代码

1. >>> Publisher.objects.filter(country='USA').delete()  

>>> Publisher.objects.filter(country='USA').delete()