django 文档参考模型

list_per_page

list_select_related

ordering

save_as

save_on_top

search_fields

WHERE(first_nameILIKE'%john%'ORlast_nameILIKE'%john%')
AND(first_nameILIKE'%lennon%'ORlast_nameILIKE'%lennon%')

Managers

Managernames

fromdjango.dbimportmodels

classPerson(models.Model):
#...
people=models.Manager()

CustomManagers

AddingextraManagermethods

classPollManager(models.Manager):
defwith_counts(self):
fromdjango.dbimportconnection
cursor=connection.cursor()
cursor.execute("""
SELECTp.id,p.question,p.poll_date,COUNT(*)
FROMpolls_opinionpollp,polls_responser
WHEREp.id=r.poll_id
GROUPBY1,2,3
ORDERBY3DESC""")
result_list=[]
forrowincursor.fetchall():
p=self.model(id=row[0],question=row[1],poll_date=row[2])
p.num_responses=row[3]
result_list.append(p)
returnresult_list

classOpinionPoll(models.Model):
question=models.CharField(maxlength=200)
poll_date=models.DateField()
objects=PollManager()

classResponse(models.Model):
poll=models.ForeignKey(Poll)
person_name=models.CharField(maxlength=50)
response=models.TextField()

ModifyinginitialManagerQuerySets

classBook(models.Model):
title=models.CharField(maxlength=100)
author=models.CharField(maxlength=50)

#First,definetheManagersubclass.
classDahlBookManager(models.Manager):
defget_query_set(self):
returnsuper(DahlBookManager,self).get_query_set().filter(author='RoaldDahl')

#ThenhookitintotheBookmodelexplicitly.
classBook(models.Model):
title=models.CharField(maxlength=100)
author=models.CharField(maxlength=50)

objects=models.Manager()#Thedefaultmanager.
dahl_objects=DahlBookManager()#TheDahl-specificmanager.

Book.dahl_objects.all()
Book.dahl_objects.filter(title='Matilda')
Book.dahl_objects.count()

classMaleManager(models.Manager):
defget_query_set(self):
returnsuper(MaleManager,self).get_query_set().filter(sex='M')

classFemaleManager(models.Manager):
defget_query_set(self):
returnsuper(FemaleManager,self).get_query_set().filter(sex='F')

classPerson(models.Model):
first_name=models.CharField(maxlength=50)
last_name=models.CharField(maxlength=50)
sex=models.CharField(maxlength=1,choices=(('M','Male'),('F','Female')))
people=models.Manager()
men=MaleManager()
women=FemaleManager()

Modelmethods

classPerson(models.Model):
first_name=models.CharField(maxlength=50)
last_name=models.CharField(maxlength=50)
birth_date=models.DateField()
address=models.CharField(maxlength=100)
city=models.CharField(maxlength=50)
state=models.USStateField()#Yes,thisisAmerica-centric...

defbaby_boomer_status(self):
"Returnstheperson'sbaby-boomerstatus."
importdatetime
ifdatetime.date(1945,8,1)<=self.birth_date<=datetime.date(1964,12,31):
return"Babyboomer"
ifself.birth_date<datetime.date(1945,8,1):
return"Pre-boomer"
return"Post-boomer"

defis_midwestern(self):
"ReturnsTrueifthispersonisfromtheMidwest."
returnself.statein('IL','WI','MI','IN','OH','IA','MO')

def_get_full_name(self):
"Returnstheperson'sfullname."
return'%s%s'%(self.first_name,self.last_name)
full_name=property(_get_full_name)

__str__

classPerson(models.Model):
first_name=models.CharField(maxlength=50)
last_name=models.CharField(maxlength=50)

def__str__(self):
return'%s%s'%(self.first_name,self.last_name)

get_absolute_url

defget_absolute_url(self):
return"/people/%i/"%self.id

<ahref="/people/{{object.id}}/">{{object.name}}</a>

<ahref="{{object.get_absolute_url}}">{{object.name}}</a>

ExecutingcustomSQL

defmy_custom_sql(self):
fromdjango.dbimportconnection
cursor=connection.cursor()
cursor.execute("SELECTfooFROMbarWHEREbaz=%s",[self.baz])
row=cursor.fetchone()
returnrow

Overridingdefaultmodelmethods

classBlog(models.Model):
name=models.CharField(maxlength=100)
tagline=models.TextField()

defsave(self):
do_something()
super(Blog,self).save()#Callthe"real"save()method.
do_something_else()

classBlog(models.Model):
name=models.CharField(maxlength=100)
tagline=models.TextField()

defsave(self):
ifself.name=="YokoOno'sblog":
return#Yokoshallneverhaveherownblog!
else:
super(Blog,self).save()#Callthe"real"save()method.

Modelsacrossfiles

frommysite.geography.modelsimportZipCode

classRestaurant(models.Model):
#...
zip_code=models.ForeignKey(ZipCode)

Usingmodels

INSTALLED_APPS=(
#...
'mysite.myapp',
#...
)

ProvidinginitialSQLdata

INSERTINTOmyapp_person(first_name,last_name)VALUES('John','Lennon');
INSERTINTOmyapp_person(first_name,last_name)VALUES('Paul','McCartney');

Database-backend-specificSQLdata