Django에서 모델 필드의 의미, 사용 방법
문서 목록
1. 필드 이름, 의미
AutoField(Field)
# int ， primary_key=True
BigAutoField(AutoField)
# bigint ， primary_key=True
： model ， id
from django.db import models
class UserInfo(models.Model):
# id
username = models.CharField(max_length=32)
class Group(models.Model):
#
nid = models.AutoField(primary_key=True)
name = models.CharField(max_length=32)
SmallIntegerField(IntegerField):
# -32768 ～ 32767
PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField)
# 0 ～ 32767
IntegerField(Field)
# ( ) -2147483648 ～ 2147483647
PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField)
# 0 ～ 2147483647
BigIntegerField(IntegerField):
# ( ) -9223372036854775808 ～ 9223372036854775807
class UnsignedIntegerField(models.IntegerField):
def db_type(self, connection):
return 'integer UNSIGNED'
PS: ，Django ：
'AutoField': 'integer AUTO_INCREMENT',
'BigAutoField': 'bigint AUTO_INCREMENT',
'BinaryField': 'longblob',
'BooleanField': 'bool',
'CharField': 'varchar(%(max_length)s)',
'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'datetime',
'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',
'DurationField': 'bigint',
'FileField': 'varchar(%(max_length)s)',
'FilePathField': 'varchar(%(max_length)s)',
'FloatField': 'double precision',
'IntegerField': 'integer',
'BigIntegerField': 'bigint',
'IPAddressField': 'char(15)',
'GenericIPAddressField': 'char(39)',
'NullBooleanField': 'bool',
'OneToOneField': 'integer',
'PositiveIntegerField': 'integer UNSIGNED',
'PositiveSmallIntegerField': 'smallint UNSIGNED',
'SlugField': 'varchar(%(max_length)s)',
'SmallIntegerField': 'smallint',
'TextField': 'longtext',
'TimeField': 'time',
'UUIDField': 'char(32)',
BooleanField(Field)
#
NullBooleanField(Field):
#
CharField(Field)
#
# max_length ， max_length
TextField(Field)
#
EmailField(CharField)：
# ，Django Admin ModelForm
IPAddressField(Field)
# ，Django Admin ModelForm IPV4
GenericIPAddressField(Field)
# ，Django Admin ModelForm Ipv4 Ipv6
# ：
protocol， Ipv4 Ipv6， 'both',"ipv4","ipv6"
unpack_ipv4， True， ::ffff:192.0.2.1 ， 192.0.2.1， ， protocol="both"
URLField(CharField)
# ，Django Admin ModelForm URL
SlugField(CharField)
# ，Django Admin ModelForm 、 、 、 （ ）
CommaSeparatedIntegerField(CharField)
# ，
UUIDField(Field)
# ，Django Admin ModelForm UUID
FilePathField(Field)
# ，Django Admin ModelForm
# ：
path,
match=None,
recursive=False,
allow_files=True,
allow_folders=False,
FileField(Field)
# ， ，
# ：
upload_to = ""
storage = None ， django.core.files.storage.FileSystemStorage
ImageField(FileField)
# ， ，
# ：
upload_to = ""
storage = None ， django.core.files.storage.FileSystemStorage
width_field=None, （ ）
height_field=None （ ）
DateTimeField(DateField)
# + YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]
DateField(DateTimeCheckMixin, Field)
# YYYY-MM-DD
TimeField(DateTimeCheckMixin, Field)
# HH:MM[:ss[.uuuuuu]]
DurationField(Field)
# ， ， bigint ，ORM datetime.timedelta
FloatField(Field)
#
DecimalField(Field)
# 10
# ：
max_digits，
decimal_places，
BinaryField(Field)
#
2. 매개변수 의미
null
db_column
db_tablespace
default
primary_key
db_index
unique
unique_for_date 【 】
unique_for_month 【 】
unique_for_year 【 】
verbose_name Admin
blank Admin
editable Admin
help_text Admin
choices Admin ，
：gf = models.IntegerField(choices=[(0, ' '),(1, ' '),],default=1)
error_messages （ ）， ；
：null, blank, invalid, invalid_choice, unique, and unique_for_date
：{'null': " .", 'invalid': ' '}
validators （ ），
from django.core.validators import RegexValidator
from django.core.validators import EmailValidator,URLValidator,DecimalValidator,\
MaxLengthValidator,MinLengthValidator,MaxValueValidator,MinValueValidator
：
test = models.CharField(
max_length=32,
error_messages={
'c1': ' 1',
'c2': ' 2',
'c3': ' 3',
},
validators=[
RegexValidator(regex='root_\d+', message=' ', code='c1'),
RegexValidator(regex='root_112233\d+', message=' ', code='c2'),
EmailValidator(message=' ', code='c3'), ]
)
3. 메타 정보 메타(데이터베이스 테이블 이름 작성 등 조작에 관여)
class UserInfo(models.Model):
nid = models.AutoField(primary_key=True)
username = models.CharField(max_length=32)
class Meta:
# app + +
db_table = "table_name"
#
index_together = [
("pub_date", "deadline"),
]
#
unique_together = (("driver", "restaurant"),)
# ，admin
verbose_name
# verbose_name s ( )
verbose_name_plural
：https://docs.djangoproject.com/en/1.10/ref/models/options/
4. 확장
1. Model ：
a. Django Admin Admiin ModelForm ， ， Model
b. Model "clean_fields" ， ：
# models.py
class UserInfo(models.Model):
nid = models.AutoField(primary_key=True)
username = models.CharField(max_length=32)
email = models.EmailField(error_messages={'invalid': ' .'})
# views.py
def index(request):
obj = models.UserInfo(username='11234', email='uu')
try:
print(obj.clean_fields())
except Exception as e:
print(e)
return HttpResponse('ok')
# Model clean ， ， ： 。
2.Admin
# admin.py
from django.contrib import admin
from model_club import models
from django import forms
class UserInfoForm(forms.ModelForm):
username = forms.CharField(error_messages={'required': ' .'})
email = forms.EmailField(error_messages={'invalid': ' .'})
age = forms.IntegerField(initial=1, error_messages={'required': ' .', 'invalid': ' .'})
class Meta:
model = models.UserInfo
# fields = ('username',)
fields = "__all__"
class UserInfoAdmin(admin.ModelAdmin):
form = UserInfoForm
admin.site.register(models.UserInfo, UserInfoAdmin)
2. 테이블 구조 *****
ForeignKey(ForeignObject) # ForeignObject(RelatedField)
to, #
to_field=None, #
on_delete=None, # ， , ：
# ：
- models.CASCADE， ，
- models.DO_NOTHING， ， IntegrityError
- models.PROTECT， ， ProtectedError
- models.SET_NULL， ， null（ FK ）
- models.SET_DEFAULT， ， （ FK ）
- models.SET， ，
a. ， ：models.SET( )
b. ， ：models.SET( )
def func():
return 10
class MyModel(models.Model):
user = models.ForeignKey(
to="User",
to_field="id"
on_delete=models.SET(func),)
related_name=None, # ， ， 【 _set】 ： obj. _set.all()
related_query_name=None, # ， ， 【 】 ： models.UserGroup.objects.filter( __ =1).values(' __ ')
limit_choices_to=None, # Admin ModelForm ， ：
# ：
- limit_choices_to={'nid__gt': 5}
- limit_choices_to=lambda : {'nid__gt': 5}
from django.db.models import Q
- limit_choices_to=Q(nid__gt=10)
- limit_choices_to=Q(nid=8) | Q(nid__gt=10)
- limit_choices_to=lambda : Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption='root')
db_constraint=True #
parent_link=False # Admin
OneToOneField(ForeignKey)
to, #
to_field=None #
on_delete=None, # ，
###### ######
# 1. +
# 2. ，
# A c_ptr_id ：
class C(models.Model):
nid = models.AutoField(primary_key=True)
part = models.CharField(max_length=12)
class A(C):
id = models.AutoField(primary_key=True)
code = models.CharField(max_length=1)
ManyToManyField(RelatedField)
to, #
related_name=None, # ， ， 【 _set】 ： obj. _set.all()
related_query_name=None, # ， ， 【 】 ： models.UserGroup.objects.filter( __ =1).values(' __ ')
limit_choices_to=None, # Admin ModelForm ， ：
# ：
- limit_choices_to={'nid__gt': 5}
- limit_choices_to=lambda : {'nid__gt': 5}
from django.db.models import Q
- limit_choices_to=Q(nid__gt=10)
- limit_choices_to=Q(nid=8) | Q(nid__gt=10)
- limit_choices_to=lambda : Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption='root')
symmetrical=None, # ，symmetrical
# ， symmetrical
models.BB.objects.filter(...)
# ：code, id, m1
class BB(models.Model):
code = models.CharField(max_length=12)
m1 = models.ManyToManyField('self',symmetrical=True)
# : bb, code, id, m1
class BB(models.Model):
code = models.CharField(max_length=12)
m1 = models.ManyToManyField('self',symmetrical=False)
through=None, # ，
through_fields=None, # ，
from django.db import models
class Person(models.Model):
name = models.CharField(max_length=50)
class Group(models.Model):
name = models.CharField(max_length=128)
members = models.ManyToManyField(
Person,
through='Membership',
through_fields=('group', 'person'),
)
class Membership(models.Model):
group = models.ForeignKey(Group, on_delete=models.CASCADE)
person = models.ForeignKey(Person, on_delete=models.CASCADE)
inviter = models.ForeignKey(
Person,
on_delete=models.CASCADE,
related_name="membership_invites",
)
invite_reason = models.CharField(max_length=64)
db_constraint=True, #
db_table=None, # ，
Stack overflow 네티즌의 답변:
This is the behaviour to adopt when the referenced object is deleted. It is not specific to django, this is an SQL standard.
There are 6 possible actions to take when such event occurs:
CASCADE : When the referenced object is deleted, also delete the objects that have references to it (When you remove a blog post for instance, you might want to delete comments as well). SQL equivalent: CASCADE . PROTECT : Forbid the deletion of the referenced object. To delete it you will have to delete all objects that reference it manually. SQL equivalent: RESTRICT . SET_NULL : Set the reference to NULL (requires the field to be nullable). For instance, when you delete a User, you might want to keep the comments he posted on blog posts, but say it was posted by an anonymous (or deleted) user. SQL equivalent: SET NULL . SET_DEFAULT : Set the default value. SQL equivalent: SET DEFAULT . SET(...) : Set a given value. This one is not part of the SQL standard and is entirely handled by Django. DO_NOTHING : Probably a very bad idea since this would create integrity issues in your database (referencing an object that actually doesn’t exist). SQL equivalent: NO ACTION . Source: Django documentation
See also the documentation of PostGreSQL for instance.
In most cases,
CASCADE is the expected behaviour, but for every ForeignKey, you should always ask yourself what is the expected behaviour in this situation. PROTECT and SET_NULL are often useful. Setting CASCADE where it should not, can potentially delete all your database in cascade, by simply deleting a single user. 3. 테이블의 조작(정방향 조회는 필드에 따라, 반방향 조회는 테이블 이름에 따라)
1. 기본 조작(추가, 삭제, 수정, 조사)
#
models.Tb1.objects.create(c1='xx', c2='oo') # ， **kwargs
obj = models.Tb1(c1='xx', c2='oo')
obj.save() # save ， 。
#
models.Tb1.objects.get(id=123) # ， （ ）
models.Tb1.objects.all() #
models.Tb1.objects.filter(name='seven') # ， , []
#
models.Tb1.objects.filter(name='seven').delete() #
#
models.Tb1.objects.filter(name='seven').update(gender='0') # ， **kwargs
# obj = models.Tb1.objects.get(id=1)
# obj.c1 = '111'
# obj.save() #
2. 표 조작 진급(소박의 더블 밑줄)
와 _set를 이용하여 테이블 간의 조작을 연결하다#
models.Tb1.objects.filter(name='seven').count()
# ，
models.Tb1.objects.filter(id__gt=1) # id 1
models.Tb1.objects.filter(id__gte=1) # id 1
models.Tb1.objects.filter(id__lt=10) # id 10
models.Tb1.objects.filter(id__lte=10) # id 10
models.Tb1.objects.filter(id__lt=10, id__gt=1) # id 1 10
# in
models.Tb1.objects.filter(id__in=[11, 22, 33]) # id 11、22、33
models.Tb1.objects.exclude(id__in=[11, 22, 33]) # not in
# isnull
Entry.objects.filter(pub_date__isnull=True)
# contains
models.Tb1.objects.filter(name__contains="ven")
models.Tb1.objects.filter(name__icontains="ven") # icontains
models.Tb1.objects.exclude(name__icontains="ven")
# range
models.Tb1.objects.filter(id__range=[1, 2]) # bettwen and
#
startswith，istartswith, endswith, iendswith,
# order by
models.Tb1.objects.filter(name='seven').order_by('id') # asc
models.Tb1.objects.filter(name='seven').order_by('-id') # desc
# group by
from django.db.models import Count, Min, Max, Sum
models.Tb1.objects.filter(c1=1).values('id').annotate(c=Count('num'))
SQL ：SELECT "app01_tb1"."id", COUNT("app01_tb1"."num") AS "c" FROM "app01_tb1" WHERE "app01_tb1"."c1" = 1 GROUP BY "app01_tb1"."id"
# limit 、offset
models.Tb1.objects.all()[10:20]
# regex ，iregex
Entry.objects.get(title__regex=r'^(An?|The) +')
Entry.objects.get(title__iregex=r'^(an?|the) +')
# date
Entry.objects.filter(pub_date__date=datetime.date(2005, 1, 1))
Entry.objects.filter(pub_date__date__gt=datetime.date(2005, 1, 1))
# year
Entry.objects.filter(pub_date__year=2005)
Entry.objects.filter(pub_date__year__gte=2005)
# month
Entry.objects.filter(pub_date__month=12)
Entry.objects.filter(pub_date__month__gte=6)
# day
Entry.objects.filter(pub_date__day=3)
Entry.objects.filter(pub_date__day__gte=3)
# week_day
Entry.objects.filter(pub_date__week_day=2)
Entry.objects.filter(pub_date__week_day__gte=2)
# hour
Event.objects.filter(timestamp__hour=23)
Event.objects.filter(time__hour=5)
Event.objects.filter(timestamp__hour__gte=12)
# minute
Event.objects.filter(timestamp__minute=29)
Event.objects.filter(time__minute=46)
Event.objects.filter(timestamp__minute__gte=29)
# second
Event.objects.filter(timestamp__second=31)
Event.objects.filter(time__second=2)
Event.objects.filter(timestamp__second__gte=31)
#
get ：
# ： id 3 。
# ，
BookInfo.objects.get(id=3)
all ：
# ： 。
BookInfo.objects.all()
filter ：
"""
：( )
__ =
"""
34 ：
a) :exact。
# ： 1 。
BookInfo.objects.get(id=1)
b) ( sql like)
# ： ' ' 。contains
BookInfo.objects.filter(btitle__contains=' ')
# ： ' ' endswith :startswith
BookInfo.objects.filter(btitle__endswith=' ')
c) isnull
# ： 。isnull
select * from booktest_bookinfo where btitle is not null;
BookInfo.objects.filter(btitle__isnull=False)
d) in
# ： id 1 3 5 。
select * from booktest_bookinfo where id in (1,3,5);
BookInfo.objects.filter(id__in = [1,3,5])
e) gt(greate than) lt(less than) gte(equal) lte
# ： id 3 。
Select * from booktest_bookinfo where id>3;
BookInfo.objects.filter(id__gt=3)
f)
# ： 1980 。
BookInfo.objects.filter(bpub_date__year=1980)
# ： 1980 1 1 。
from datetime import date
BookInfo.objects.filter(bpub_date__gt=date(1980,1,1))
exclude ：
# ： id 3 。
BookInfo.objects.exclude(id=3)
order_by ：
： 。 ， “-”
# ： ， id 。
BookInfo.objects.all().order_by('id')
# ： ， id 。
BookInfo.objects.all().order_by('-id')
# ： id 3 。
BookInfo.objects.filter(id__gt=3).order_by('-bread')
3. 기타
# extra
#
extra(self, select=None, where=None, params=None, tables=None, order_by=None, select_params=None)
Entry.objects.extra(select={'new_id': "select col from sometable where othercol > %s"}, select_params=(1,))
Entry.objects.extra(where=['headline=%s'], params=['Lennon'])
Entry.objects.extra(where=["foo='a' OR bar = 'a'", "baz = 'a'"])
Entry.objects.extra(select={'new_id': "select id from tb where id > %s"}, select_params=(1,), order_by=['-nid'])
# F
#
from django.db.models import F
models.Tb1.objects.update(num=F('num')+1)
# Q
#
# ：
Q(nid__gt=10)
Q(nid=8) | Q(nid__gt=10)
Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption='root')
# ：
con = Q()
q1 = Q()
q1.connector = 'OR'
q1.children.append(('id', 1))
q1.children.append(('id', 10))
q1.children.append(('id', 9))
q2 = Q()
q2.connector = 'OR'
q2.children.append(('c1', 1))
q2.children.append(('c1', 10))
q2.children.append(('c1', 9))
con.add(q1, 'AND')
con.add(q2, 'AND')
models.Tb1.objects.filter(con)
# SQL
#
from django.db import connection, connections
cursor = connection.cursor() # cursor = connections['default'].cursor()
cursor.execute("""SELECT * from auth_user where id = %s""", [1])
row = cursor.fetchone()
4. 테이블 연결 작업(이중 밑줄 사용)
class UserProfile(models.Model):
user_info = models.OneToOneField('UserInfo')
username = models.CharField(max_length=64)
password = models.CharField(max_length=64)
def __unicode__(self):
return self.username
class UserInfo(models.Model):
user_type_choice = (
(0, u' '),
(1, u' '),
)
user_type = models.IntegerField(choices=user_type_choice)
name = models.CharField(max_length=32)
email = models.CharField(max_length=32)
address = models.CharField(max_length=128)
def __unicode__(self):
return self.name
class UserGroup(models.Model):
caption = models.CharField(max_length=64)
user_info = models.ManyToManyField('UserInfo')
def __unicode__(self):
return self.caption
class Host(models.Model):
hostname = models.CharField(max_length=64)
ip = models.GenericIPAddressField()
user_group = models.ForeignKey('UserGroup')
def __unicode__(self):
return self.hostname
1. 일대일 운영
user_info_obj = models.UserInfo.objects.filter(id=1).first()
print(user_info_obj.user_type)
print(user_info_obj.get_user_type_display())
print(user_info_obj.userprofile.password)
user_info_obj = models.UserInfo.objects.filter(id=1).values('email', 'userprofile__username').first()
print(user_info_obj.keys())
print(user_info_obj.values())
2. 일대다
__ 연결. 연결3. 다대다
user_info_obj = models.UserInfo.objects.get(name=u' ')
user_info_objs = models.UserInfo.objects.all()
group_obj = models.UserGroup.objects.get(caption='CEO')
group_objs = models.UserGroup.objects.all()
-------------------------------------------------------------
#
group_obj.user_info.add(user_info_obj)
group_obj.user_info.add(*user_info_objs) #
#
group_obj.user_info.remove(user_info_obj)
group_obj.user_info.remove(*user_info_objs)
#
user_info_obj.usergroup_set.add(group_obj)
user_info_obj.usergroup_set.add(*group_objs)
#
user_info_obj.usergroup_set.remove(group_obj)
user_info_obj.usergroup_set.remove(*group_objs)
#
print group_obj.user_info.all()
print group_obj.user_info.all().filter(id=1)
#
print user_info_obj.usergroup_set.all() # __set
print user_info_obj.usergroup_set.all().filter(caption='CEO')
print user_info_obj.usergroup_set.all().filter(caption='DBA')
5. 확장(파일 업로드)
def upload_file(request):
if request.method == "POST":
obj = request.FILES.get('fafafa')
f = open(obj.name, 'wb')
for chunk in obj.chunks(): # chunks
f.write(chunk)
f.close()
return render(request, 'file.html')
# Form
class FileForm(forms.Form):
ExcelFile = forms.FileField()
# Model
from django.db import models
class UploadFile(models.Model):
userid = models.CharField(max_length = 30)
file = models.FileField(upload_to = './upload/')
date = models.DateTimeField(auto_now_add=True)
# View
def UploadFile(request):
uf = AssetForm.FileForm(request.POST,request.FILES)
if uf.is_valid():
upload = models.UploadFile()
upload.userid = 1
upload.file = uf.cleaned_data['ExcelFile']
upload.save()
print upload.file
6. 대량 삭제
models.SyncRecord.objects.filter(create_time__lte=clear_timestamp).delete() 여과된 데이터에 따라 직접 삭제 호출models.SyncRecord.objects.filter(
pk__in=(models.SyncRecord.objects.order_by('create_time').values_list('pk')[:5])
).delete()
# django ORM sql page/limit ， orm sql ， page/limit
id_query_set = models.SyncRecord.objects.order_by('create_time')[:clear_count].values_list('id')
# django queryset
clear_id_list = [int(i[0]) for i in id_query_set]
models.SyncRecord.objects.filter(id__in=clear_id_list).delete()
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