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【Django】--Model字段
阅读量:4654 次
发布时间:2019-06-09

本文共 19832 字,大约阅读时间需要 66 分钟。

参考地址:http://www.cnblogs.com/wupeiqi/articles/6216618.html 所有字段    AutoField(Field)     --int自增列,必须填入参数primary_key=True   BigAutoField(AutoField)     --bigint自增列,必须填入参数primary_key=True     注意:当model中没有自增列,则自动会创建一个列名为id的列               from django.db import models     class UserInfo(models.Model):       #自动创建一个列名为id的且为自增的整数列       username = models.CharField(max_length=32)     class Group(modes.Model):       #自定义自增列       nid = models.AutoField(primary_key = True)       name = models.CharField(max_length=32)   SmallIntegerField(IntegerField):     --小整数  -32768 ~ 32767   PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin,IntegerField)     --正小整数  0 ~ 32767   PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin,IntergerField)     --正小整数  0 ~ 32767   IntegerField(Field)     --整数列(有符号的) -2147483648 ~ 2147483647   PositiveIntegerField(PositiveIntegerRelDbTypeMixin,IntegerField)     --正整数  0 ~ 2147483647   BigINtegerField(IntegerField):     --长整型(有符号的) -9223372036854775808 ~ 9223372036854775807      自定义无符号整数字段     class UnsignedIntegerFIeld(models.IntegerField):       def db_type(self,connection):         return "integer UNSIGNED"     PS:返回值为字段在数据库中的属性,Django字段默认的值为:       "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",       "PositiveSmallIntegerField":"smallint UNSIGNED",       "SlugField":"varchar(%(max_length)s)",       "SmallIntegerField":"smallint",       "TextField":"longtext",       "TimeField":"time",       "UUIDField":"char(32)",   BooleanField(Field)      --布尔值类型   NullBooleanField(Field):      --可以为空的布尔值   CharField(Field)      --字符类型      --必须提供max_length参数,max_length表示字符长度   TextField(Field)      --文本类型   EmailField(CharField):     --字符串类型,Django Admin以及ModelForm中提供验证机制   IPAddressField(Field)     --字符串类型,Django Admin以及ModelForm中提供验证  IPV4 机制   GenericIPAddressField(Field)          --字符串类型,Django Admin以及ModelForm中提供验证 IPV4 和 IPV6     --参数:       protocol,用于指定IPV4或IPV6,"both","ipv4","ipv6" 解析为192.0.2.1,开启此功能,需要protocol="both"   URLField(CharField)     --字符串类型,Django Admin以及ModelForm中提供验证  URL   SlugField(CharField)     --字符串类型,Django Admin 以及ModelForm中提供验证支持字母,数字,下划线,连接符(减号)   CommaSeparatedIntegerField(CharField)     --字符串类型,格式必须为逗号分割的数字   UUIDField(Field)     --字符串类型,Django Admin以及ModelForm中提供对UUID格式的验证   FilePathField(Field)     --字符串,Django Admin以及MOdelForm中提供读取文件夹下文件的功能     --参数:       path,  文件夹路径       match=None,  正则匹配       recursive = False,  递归下面的文件夹       allow_files = True, 允许文件       allow_folders =False  允许文件夹   FileField(Field)     --字符串,路径保存在数据库,文件上传到指定目录     --参数:       upload_to = ""  上传文件的保存路径       storage = None  存储组件,默认 django.core.files.storage.FileSystemStorage   ImageField(FileField)     --字符串,路径保存在数据库,文件上传到指定目录     --参数:       upload_to = "" 上传文件的保存路径       storage = None 存储组件,默认 django.core.files.storage.FileSystemStorage     width_field=None,上传图片的高度保存到数据库字段名(字符串)     height_field = None,  上传图片的宽度保存的数据库字段名(字符串) DateTimeField(DateField)   --日期+时间格式 YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] DateField(DateTimeCheckMixin,Field)   --日期格式  YYYY-MM-DD TimeField(DateTimeCheckMixin,Field)   --时间格式  HH:MM[:SS[.uuuuuu]] DurationField(Field)   --长整数,时间间隔,数据库中按照bigint存储,ORM中获取的值为 datetime.timedelta类型   FloatField(Field)     --浮点型   DecimalField(Field)     --10进制小数     --参数:       max_digits, 小数总长度       decimal_places,小数位长度   BinaryField 参数:   null           数据库中字段是否可以为空   db_column      数据库中字段的列名   db_tablespace   default        数据库中字段的默认值   primary_key    数据库中字段   db_index       数据库中字段是否可以建立索引   unique     数据库中字段是否可以建立唯一索引   unique_for_date 数据库中字段【日期】部分是否可以建立唯一索引   unique_for_month 数据库中字段【月】部分是否可以建立唯一索引   unique_for_year  数据库中字段【年】部分是否可以建立唯一索引   verbose_name    Admin中显示的字段名称   blank   Admin中是否允许用户输入为空   editable  Admin中是否可以编辑   help_text   Admin中该字段的提示信息   choices  Admin中显示选择框的内容,用不变动的数据放在内存中从而避免跨表操作      如:gf = models.IntegerField(choices=[(0,"杂杂"),(1,"啊啊“),],default=1)     error_messages  自定义错误信息(字典类型),从而定制想要显示的错误信息;     字典键:null,blank,invalid,invalid_choice,unique,and unique_for_date       如:{"null":"不能为空","invalid":"格式错误"}   validators  自定义错误验证(列表类型),从而定制想要的验证规则           from django.core.validators import egexValidator           from django.core.validators import mailValidator,             URLValidator,DecimalValidator,       MaxLengthValidator,MinLengthValidator,MaxValidator,MinValidator如:         test = models.CharField(           max_length = 32,           error_messages = {
          "c1":"优先错信息1",           ”c2“:"优先错信息2",           "c3":"优先错信息3",           },           validators = [             RegexValidator(regex="root_\d+",message="错误了,code="c1"),             RegexValidator(regex="root_112233\d+messae="又错误了",code="c2"),             EmailValidator(message="又错误了,code="c3"),]         ) 元信息      class UserInfo(models.Model):     nid = models.AutoField(primary_key=True)     username = models.CharField(max_length=32)     class Meta;       #数据库中生成的表名称 默认app名称 + 下划线 +类名       db_table = "table_name"       #联合索引       index_together = [       ("pub_date","deadline"),       ]              #联合唯一索引       unique_together = (("driver","restaurant"),)        #admin中显示的表名称          verbose_name       #verbose_name 加s              verbose_name_plural   更多:https://docs.djangoproject.com/en/1.10/ref/models/options/   注:     1.触发Model中的验证和错误提示有两种方式:       a. Django Admin中的错误信息会优先根据Admiin内部的ModelForm错误信息提示,如果都成功,才来检查Model的字段并显示指定错误信息       b.调用Model对象的 clean_fields 方法,如:             # models.py             class UserInfo(models.Model):                 nid = models.AutoField(primary_key=True)                 username = models.CharField(max_length=32)                 email = models.EmailField(error_messages={'invalid': '格式错了.'})             # 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的clean方法是一个钩子,可用于定制操作,如:上述的异常处理。     2.Admin中修改错误提示               # 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': '用户名不能为空.'})             email = forms.EmailField(error_messages={'invalid': '邮箱格式错误.'})             age = forms.IntegerField(initial=1, error_messages={'required': '请输入数值.', 'invalid': '年龄必须为数值.'})             class Meta:                 model = models.UserInfo                 # fields = ('username',)                 fields = "__all__"         class UserInfoAdmin(admin.ModelAdmin):             form = UserInfoForm         admin.site.register(models.UserInfo, UserInfoAdmin) 四、多表关系     ForeignKey(ForeignObject) # ForeignObject(RelatedField)         to,                         # 要进行关联的表名         to_field=None,              # 要关联的表中的字段名称         on_delete=None,             # 当删除关联表中的数据时,当前表与其关联的行的行为                                         - models.CASCADE,删除关联数据,与之关联也删除                                         - models.DO_NOTHING,删除关联数据,引发错误IntegrityError                                         - models.PROTECT,删除关联数据,引发错误ProtectedError                                         - models.SET_NULL,删除关联数据,与之关联的值设置为null(前提FK字段需要设置为可空)                                         - models.SET_DEFAULT,删除关联数据,与之关联的值设置为默认值(前提FK字段需要设置默认值)                                         - models.SET,删除关联数据,                                                       a. 与之关联的值设置为指定值,设置:models.SET(值)                                                       b. 与之关联的值设置为可执行对象的返回值,设置:models.SET(可执行对象)                                                         def func():                                                             return 10                                                         class MyModel(models.Model):                                                             user = models.ForeignKey(                                                                 to="User",                                                                 to_field="id"                                                                 on_delete=models.SET(func),)         related_name=None,          # 反向操作时,使用的字段名,用于代替 【表名_set】 如: obj.表名_set.all()         related_query_name=None,    # 反向操作时,使用的连接前缀,用于替换【表名】     如: models.UserGroup.objects.filter(表名__字段名=1).values('表名__字段名')         limit_choices_to=None,      # 在Admin或ModelForm中显示关联数据时,提供的条件:                                     # 如:                                             - 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          # 是否在数据库中创建外键约束         parent_link=False           # 在Admin中是否显示关联数据     OneToOneField(ForeignKey)         to,                         # 要进行关联的表名         to_field=None               # 要关联的表中的字段名称         on_delete=None,             # 当删除关联表中的数据时,当前表与其关联的行的行为                                     ###### 对于一对一 ######                                     # 1. 一对一其实就是 一对多 + 唯一索引                                     # 2.当两个类之间有继承关系时,默认会创建一个一对一字段                                     # 如下会在A表中额外增加一个c_ptr_id列且唯一:                                             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,                         # 要进行关联的表名         related_name=None,          # 反向操作时,使用的字段名,用于代替 【表名_set】 如: obj.表名_set.all()         related_query_name=None,    # 反向操作时,使用的连接前缀,用于替换【表名】     如: models.UserGroup.objects.filter(表名__字段名=1).values('表名__字段名')         limit_choices_to=None,      # 在Admin或ModelForm中显示关联数据时,提供的条件:                                     # 如:                                             - 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,           # 仅用于多对多自关联时,symmetrical用于指定内部是否创建反向操作的字段                                     # 做如下操作时,不同的symmetrical会有不同的可选字段                                         models.BB.objects.filter(...)                                         # 可选字段有:code, id, m1                                             class BB(models.Model):                                             code = models.CharField(max_length=12)                                             m1 = models.ManyToManyField('self',symmetrical=True)                                         # 可选字段有: bb, code, id, m1                                             class BB(models.Model):                                             code = models.CharField(max_length=12)                                             m1 = models.ManyToManyField('self',symmetrical=False)         through=None,               # 自定义第三张表时,使用字段用于指定关系表         through_fields=None,        # 自定义第三张表时,使用字段用于指定关系表中那些字段做多对多关系表                                         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,         # 是否在数据库中创建外键约束         db_table=None,              # 默认创建第三张表时,数据库中表的名称     练习:使用ForeignKey 、ManyToManyField、OneToOneField创建表 五、操作     基本操作:         # 增         #         # models.Tb1.objects.create(c1='xx', c2='oo')  增加一条数据,可以接受字典类型数据 **kwargs         # obj = models.Tb1(c1='xx', c2='oo')         # obj.save()         # 查         #         # models.Tb1.objects.get(id=123)         # 获取单条数据,不存在则报错(不建议)         # models.Tb1.objects.all()               # 获取全部         # models.Tb1.objects.filter(name='seven') # 获取指定条件的数据         # models.Tb1.objects.exclude(name='seven') # 获取指定条件的数据         # 删         #         # models.Tb1.objects.filter(name='seven').delete() # 删除指定条件的数据         # 改         # models.Tb1.objects.filter(name='seven').update(gender='0')  # 将指定条件的数据更新,均支持 **kwargs         # obj = models.Tb1.objects.get(id=1)         # obj.c1 = '111'         # obj.save()                                                 # 修改单条数据     进阶操作:         # 获取个数         #         # models.Tb1.objects.filter(name='seven').count()         # 大于,小于         #         # models.Tb1.objects.filter(id__gt=1)              # 获取id大于1的值         # models.Tb1.objects.filter(id__gte=1)              # 获取id大于等于1的值         # models.Tb1.objects.filter(id__lt=10)             # 获取id小于10的值         # models.Tb1.objects.filter(id__lte=10)             # 获取id小于10的值         # models.Tb1.objects.filter(id__lt=10, id__gt=1)   # 获取id大于1 且 小于10的值         # in         #         # models.Tb1.objects.filter(id__in=[11, 22, 33])   # 获取id等于11、22、33的数据         # 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大小写不敏感         # models.Tb1.objects.exclude(name__icontains="ven")         # range         #         # models.Tb1.objects.filter(id__range=[1, 2])   # 范围bettwen and         # 其他类似         #         # 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'))         # 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正则匹配,iregex 不区分大小写         #         # 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)     其他操作:         # 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         #         # 方式一:         # Q(nid__gt=10)         # Q(nid=8) | Q(nid__gt=10)         # Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption='root')         # 方式二:         # 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)         # 执行原生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()                                 

 

转载于:https://www.cnblogs.com/bk770466199/p/6220568.html

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