第八章(5)

1. 元信息
2. 多表关系
3. 反向查找
4. ORM操作
5. 进阶操作
6. 其它操作
7. 高效率关联表
8. models自带验证
9. models内置钩子
10. from,choices
11. Form类
12. From内置钩子验证
13. obj.is_valid()错误信息
14. From验证

1，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


#最前缀的模式
			select * from where name='xxx'
			select * from where name='xxx' and email='xx'
			select * from where email='xx' 无法命中
			
			unique_together = (("driver","restaurant"),)

https://www.cnblogs.com/wupeiqi/articles/6216618.html

2，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

3，反向操作

from django db import models

class UserType(models.Model):
	name = models.CharField(max_length=32)
	
class User(models.Model):
	user = models.CharField(max_length=64)
	pwd = models.CharField(max_length=64)
	ut = models.FareignKey(to='UserType',to_field='id')
	
v = User.objects.all()
for item in v:
	item.user
	item.pwd
	item.ut.name

User.objects.all().values('user','ut_name')


###
v = UserType.objects.all()
for item in v:
	item.name
	item.id
	item.user_set.all()
	
UserType.objects.all().values('name','user_set')

4，ORM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()                                                 # 修改单条数据基本操作

5，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 是否为空 
        # Entry.objects.filter(pub_date__isnull=True)

        # contains (like)
        #
        # 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  范围
        #
        # models.Tb1.objects.filter(id__range=[1, 2])   # 范围bettwen and

        # 其他类似 xxx开头 xx结尾
        #
        # startswith，istartswith, endswith, iendswith,

        # order by 排序
        #
        # models.Tb1.objects.filter(name='seven').order_by('id')    # asc  正向排序
        # models.Tb1.objects.filter(name='seven').order_by('-id')   # desc  逆向排序

        # group by  分组 统计
        #
        # 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 分页
        #
        # 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) +')
        
        按时间查找
        # 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)

6，其他操作

##################################################################
# PUBLIC METHODS THAT ALTER ATTRIBUTES AND RETURN A NEW QUERYSET #
##################################################################

def all(self)
    # 获取所有的数据对象

def filter(self, *args, **kwargs)
    # 条件查询
    # 条件可以是：参数，字典，Q

def exclude(self, *args, **kwargs)
    # 条件查询
    # 条件可以是：参数，字典，Q

def select_related(self, *fields)
     性能相关：表之间进行join连表操作，一次性获取关联的数据。
     model.tb.objects.all().select_related()
     model.tb.objects.all().select_related('外键字段')
     model.tb.objects.all().select_related('外键字段__外键字段')

def prefetch_related(self, *lookups)
    性能相关：多表连表操作时速度会慢，使用其执行多次SQL查询在Python代码中实现连表操作。
            # 获取所有用户表
            # 获取用户类型表where id in (用户表中的查到的所有用户ID)
            models.UserInfo.objects.prefetch_related('外键字段')



            from django.db.models import Count, Case, When, IntegerField
            Article.objects.annotate(
                numviews=Count(Case(
                    When(readership__what_time__lt=treshold, then=1),
                    output_field=CharField(),
                ))
            )

            students = Student.objects.all().annotate(num_excused_absences=models.Sum(
                models.Case(
                    models.When(absence__type='Excused', then=1),
                default=0,
                output_field=models.IntegerField()
            )))

def annotate(self, *args, **kwargs)
    # 用于实现聚合group by查询

    from django.db.models import Count, Avg, Max, Min, Sum

    v = models.UserInfo.objects.values('u_id').annotate(uid=Count('u_id'))
    # SELECT u_id, COUNT(ui) AS `uid` FROM UserInfo GROUP BY u_id

    v = models.UserInfo.objects.values('u_id').annotate(uid=Count('u_id')).filter(uid__gt=1)
    # SELECT u_id, COUNT(ui_id) AS `uid` FROM UserInfo GROUP BY u_id having count(u_id) > 1

    v = models.UserInfo.objects.values('u_id').annotate(uid=Count('u_id',distinct=True)).filter(uid__gt=1)
    # SELECT u_id, COUNT( DISTINCT ui_id) AS `uid` FROM UserInfo GROUP BY u_id having count(u_id) > 1

def distinct(self, *field_names)
    # 用于distinct去重
    models.UserInfo.objects.values('nid').distinct()
    # select distinct nid from userinfo

    注：只有在PostgreSQL中才能使用distinct进行去重

def order_by(self, *field_names)
    # 用于排序
    models.UserInfo.objects.all().order_by('-id','age')

def extra(self, select=None, where=None, params=None, tables=None, order_by=None, select_params=None)
    # 构造额外的查询条件或者映射，如：子查询

    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'])

 def reverse(self):
    # 倒序
    models.UserInfo.objects.all().order_by('-nid').reverse()
    # 注：如果存在order_by，reverse则是倒序，如果多个排序则一一倒序


 def defer(self, *fields):
    models.UserInfo.objects.defer('username','id')
    或
    models.UserInfo.objects.filter(...).defer('username','id')
    #映射中排除某列数据

 def only(self, *fields):
    #仅取某个表中的数据
     models.UserInfo.objects.only('username','id')
     或
     models.UserInfo.objects.filter(...).only('username','id')

 def using(self, alias):
     指定使用的数据库，参数为别名（setting中的设置）


##################################################
# PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS #
##################################################

def raw(self, raw_query, params=None, translations=None, using=None):
    # 执行原生SQL
    models.UserInfo.objects.raw('select * from userinfo')

    # 如果SQL是其他表时，必须将名字设置为当前UserInfo对象的主键列名
    models.UserInfo.objects.raw('select id as nid from 其他表')

    # 为原生SQL设置参数
    models.UserInfo.objects.raw('select id as nid from userinfo where nid>%s', params=[12,])

    # 将获取的到列名转换为指定列名
    name_map = {'first': 'first_name', 'last': 'last_name', 'bd': 'birth_date', 'pk': 'id'}
    Person.objects.raw('SELECT * FROM some_other_table', translations=name_map)

    # 指定数据库
    models.UserInfo.objects.raw('select * from userinfo', using="default")

    ################### 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() # fetchall()/fetchmany(..)


def values(self, *fields):
    # 获取每行数据为字典格式

def values_list(self, *fields, **kwargs):
    # 获取每行数据为元祖

def dates(self, field_name, kind, order='ASC'):
    # 根据时间进行某一部分进行去重查找并截取指定内容
    # kind只能是："year"（年）, "month"（年-月）, "day"（年-月-日）
    # order只能是："ASC"  "DESC"
    # 并获取转换后的时间
        - year : 年-01-01
        - month: 年-月-01
        - day  : 年-月-日

    models.DatePlus.objects.dates('ctime','day','DESC')

def datetimes(self, field_name, kind, order='ASC', tzinfo=None):
    # 根据时间进行某一部分进行去重查找并截取指定内容，将时间转换为指定时区时间
    # kind只能是 "year", "month", "day", "hour", "minute", "second"
    # order只能是："ASC"  "DESC"
    # tzinfo时区对象
    models.DDD.objects.datetimes('ctime','hour',tzinfo=pytz.UTC)
    models.DDD.objects.datetimes('ctime','hour',tzinfo=pytz.timezone('Asia/Shanghai'))

    """
    pip3 install pytz
    import pytz
    pytz.all_timezones
    pytz.timezone(‘Asia/Shanghai’)
    """

def none(self):
    # 空QuerySet对象


####################################
# METHODS THAT DO DATABASE QUERIES #
####################################

def aggregate(self, *args, **kwargs):
   # 聚合函数，获取字典类型聚合结果
   from django.db.models import Count, Avg, Max, Min, Sum
   result = models.UserInfo.objects.aggregate(k=Count('u_id', distinct=True), n=Count('nid'))
   ===> {'k': 3, 'n': 4}

def count(self):
   # 获取个数

def get(self, *args, **kwargs):
   # 获取单个对象

def create(self, **kwargs):
   # 创建对象

def bulk_create(self, objs, batch_size=None):
    # 批量插入
    # batch_size表示一次插入的个数
    objs = [
        models.DDD(name='r11'),
        models.DDD(name='r22')
    ]
    models.DDD.objects.bulk_create(objs, 10)

def get_or_create(self, defaults=None, **kwargs):
    # 如果存在，则获取，否则，创建
    # defaults 指定创建时，其他字段的值
    obj, created = models.UserInfo.objects.get_or_create(username='root1', defaults={'email': '1111111','u_id': 2, 't_id': 2})

def update_or_create(self, defaults=None, **kwargs):
    # 如果存在，则更新，否则，创建
    # defaults 指定创建时或更新时的其他字段
    obj, created = models.UserInfo.objects.update_or_create(username='root1', defaults={'email': '1111111','u_id': 2, 't_id': 1})

def first(self):
   # 获取第一个

def last(self):
   # 获取最后一个

def in_bulk(self, id_list=None):
   # 根据主键ID进行查找
   id_list = [11,21,31]
   models.DDD.objects.in_bulk(id_list)

def delete(self):
   # 删除

def update(self, **kwargs):
    # 更新

def exists(self):
   # 是否有结果

其他操作

select id,count(id) from tab1 group by id having count(id) > 15;

#Entry 跨表查询 select,where
#select 
Entry.objects.filter().extra(select={'cid': "%s"},select_params=[1])
select * 1 as cid from tab1;

Entry.objects.extra(select={'new_id': "select col from sometable where othercol = %s" },select_params=[1])

select * (select name from tab2 where nid = id) as new_id from tab1;

Entry.objects.extra(select={'new_id': "func(id)"})
select * (select name from tb2 where nid = id) as new_id from tab1;

#where
Entry.objects.extra(where=['headline=1','nid>1'])
Entry.objects.extra(where=['headline=1 or nid=1'])
Entry.objects.extra(where=['func(ctime)=1 or nid=1'],params=[])

7，高效率关联表

select_related
	users = models.User.objects.all().select_related('ut')
	for row in users:
		print(row.user,row.pwd,row.ut_id)
		print(row.ut.name)
		print(row.tu.name)  #再发一次SQL请求
		
prefetch_related
	users = models.User.objects.filter(id_gt=30).prefetch_related('ut','tu')
	select * from users where id > 30
	select * from user_type where id in [1,2]
	
	for row in users:
		print(row.user,row.pwd,row.ut_id)
		print(row.ut.name)	

8，models自带验证

obj = models.UserInfo(name='alex',email='alex')
obj.full_clean()
obj.save()

return HttpResponse('index')

9，models内置钩子

class UserInfo(models.Model):
	name = models.CharField(max_length=32)
	c = UserInfo.objects.filter(name=self.name).count()
	if c:
		raise ValidationError(message='用户名已经存在'，code='li')

##############
from django.forms import vidgets

class UserInForm(forms.Form):
	user = fields.CharField(
		required=False,
		widget=widgets.Textarea(attrs={'class':'c1'})
		)
		pwd = fields.CharField(
			max_length=12,
			widget=widgets.PasswordInput(attrs={'class':'c1'})
			)
			
			#f 验证
			#生成HTML （保留上一次提交的数据）
			
			#新URL方式操作(Form方式)
			#Ajax请求 验证（*） + 生成HTML 验证(*)

10，from,choices

models.py

from django.db import models

# Create your models here.
class UserInfo(models.Model):
    name = models.CharField(max_length=32)
    email = models.EmailField()

    def clean(self):
        from django.core.exceptions import ValidationError
        c = UserInfo.objects.filter(name=self.name).count()
        if c:
            raise ValidationError(message='用户名已经存在',code='li')

class UserType(models.Model):
    name = models.CharField(max_length=32)
    
   def __str__(self):
        return self.name

###########
from.py

from django.forms import widgets
from django import forms
from django.forms import fields
from app import models
from django.forms.models import ModelChoiceField,ModelMultipleChoiceField

class UserInfoForm(forms.Form):
    user = fields.CharField(
        required=False,
        widget=widgets.Textarea(attrs={'class':'c1'})
    )
    pwd = fields.CharField(
        max_length=12,
        widget=widgets.PasswordInput(attrs={'class':'c1'})
    )

    user_type = fields.ChoiceField(
    choices = [],
    widget=widgets.Select
    )

    user_type2 = fields.ChoiceField(widget=widgets.Select(choices=[]))
    
    #django自带
    #ModelMultipleChoiceField多选
     user_type3 = ModelChoiceField(
        empty_label='请选择类型',
        queryset=models.UserType.objects.all(),
        to_field_name='id'

    )

    def __init__(self,*args,**kwargs):
        super(UserInfoForm,self).__init__(*args,**kwargs)

        self.fields['user_type'].choices = models.UserType.objects.values_list('id','name')
        self.fields['user_type2'].widget.choices = models.UserType.objects.values_list('id','name')


#########
index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <p>{{ obj.user }}</p>
    <p>{{ obj.pwd }}</p>
    <p>{{ obj.user_type }}</p>
    <p>{{ obj.user_type2 }}</p>
    <p>{{ obj.user_type3 }}</p>
</body>
</html>

11，Form类

创建Form类时，主要涉及到 【字段】 和 【插件】，字段用于对用户请求数据的验证，插件用于自动生成HTML;

1、Django内置字段如下：

http://www.cnblogs.com/wupeiqi/articles/6144178.html

Field
    required=True,               是否允许为空
    widget=None,                 HTML插件
    label=None,                  用于生成Label标签或显示内容
    initial=None,                初始值
    help_text='',                帮助信息(在标签旁边显示)
    error_messages=None,         错误信息 {'required': '不能为空', 'invalid': '格式错误'}
    show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件（可用于检验两次输入是否一直）
    validators=[],               自定义验证规则
    localize=False,              是否支持本地化
    disabled=False,              是否可以编辑
    label_suffix=None            Label内容后缀
 
 
CharField(Field)
    max_length=None,             最大长度
    min_length=None,             最小长度
    strip=True                   是否移除用户输入空白
 
IntegerField(Field)
    max_value=None,              最大值
    min_value=None,              最小值
 
FloatField(IntegerField)
    ...
 
DecimalField(IntegerField)
    max_value=None,              最大值
    min_value=None,              最小值
    max_digits=None,             总长度
    decimal_places=None,         小数位长度
 
BaseTemporalField(Field)
    input_formats=None          时间格式化   
 
DateField(BaseTemporalField)    格式：2015-09-01
TimeField(BaseTemporalField)    格式：11:12
DateTimeField(BaseTemporalField)格式：2015-09-01 11:12
 
DurationField(Field)            时间间隔：%d %H:%M:%S.%f
    ...
 
RegexField(CharField)
    regex,                      自定制正则表达式
    max_length=None,            最大长度
    min_length=None,            最小长度
    error_message=None,         忽略，错误信息使用 error_messages={'invalid': '...'}
 
EmailField(CharField)      
    ...
 
FileField(Field)
    allow_empty_file=False     是否允许空文件
 
ImageField(FileField)      
    ...
    注：需要PIL模块，pip3 install Pillow
    以上两个字典使用时，需要注意两点：
        - form表单中 enctype="multipart/form-data"
        - view函数中 obj = MyForm(request.POST, request.FILES)
 
URLField(Field)
    ...
 
 
BooleanField(Field)  
    ...
 
NullBooleanField(BooleanField)
    ...
 
ChoiceField(Field)
    ...
    choices=(),                选项，如：choices = ((0,'上海'),(1,'北京'),)
    required=True,             是否必填
    widget=None,               插件，默认select插件
    label=None,                Label内容
    initial=None,              初始值
    help_text='',              帮助提示
 
 
ModelChoiceField(ChoiceField)
    ...                        django.forms.models.ModelChoiceField
    queryset,                  # 查询数据库中的数据
    empty_label="---------",   # 默认空显示内容
    to_field_name=None,        # HTML中value的值对应的字段
    limit_choices_to=None      # ModelForm中对queryset二次筛选
     
ModelMultipleChoiceField(ModelChoiceField)
    ...                        django.forms.models.ModelMultipleChoiceField
 
 
     
TypedChoiceField(ChoiceField)
    coerce = lambda val: val   对选中的值进行一次转换
    empty_value= ''            空值的默认值
 
MultipleChoiceField(ChoiceField)
    ...
 
TypedMultipleChoiceField(MultipleChoiceField)
    coerce = lambda val: val   对选中的每一个值进行一次转换
    empty_value= ''            空值的默认值
 
ComboField(Field)
    fields=()                  使用多个验证，如下：即验证最大长度20，又验证邮箱格式
                               fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])
 
MultiValueField(Field)
    PS: 抽象类，子类中可以实现聚合多个字典去匹配一个值，要配合MultiWidget使用
 
SplitDateTimeField(MultiValueField)
    input_date_formats=None,   格式列表：['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']
    input_time_formats=None    格式列表：['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
 
FilePathField(ChoiceField)     文件选项，目录下文件显示在页面中
    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
    required=True,
    widget=None,
    label=None,
    initial=None,
    help_text=''
 
GenericIPAddressField
    protocol='both',           both,ipv4,ipv6支持的IP格式
    unpack_ipv4=False          解析ipv4地址，如果是::ffff:192.0.2.1时候，可解析为192.0.2.1， PS：protocol必须为both才能启用
 
SlugField(CharField)           数字，字母，下划线，减号（连字符）
    ...
 
UUIDField(CharField)           uuid类型

12，From内置钩子验证

#####
views.py

from django.shortcuts import render
from app.forms import  RegisterForm
# Create your views here.

def index(request):
    if request.method == "GET":
        obj =  RegisterForm()
        #传递默认值
        #obj =  RegisterForm({'user':'alex'})
        return render(request,'index.html',{'obj':obj})

    elif request.method == "POST":
        obj =  RegisterForm(request.POST,request.FILES)
        obj.is_valid()

####
froms.py

from django.core.exceptions import ValidationError
class RegisterForm(forms.Form):
    user = fields.CharField()
    email = fields.EmailField


    def clean_user(self):
        c = models.UserInfo.objects.filter(name=self.cleaned_data['user']).count()
        if not c:
            return self.cleaned_data['user']
        else:
            raise ValidationError('用户名已经存在',code='xx')

    def clean_email(self):
        return self.cleaned_data['email']

class LoginFrom(forms.Form):
    user = fields.CharField()
    pwd = fields.CharField()
    #自定义表达式
    #pwd = fields.CharField(validators=[])
    
    #验证用户是否存在
    def clean_user(self):
        c = models.UserInfo.objects.filter(name=self.cleaned_data['user']).count()
        if not c:
            return self.cleaned_data['user']
        else:
            raise ValidationError('用户名已经存在', code='xx')
   
   
    #验证密码是否正确
    def clean(self):
        c = models.UserInfo.objects.filter(name=self.cleaned_data['user'],pwd=self.cleaned_data['password']).count()
        if c:
            return self.cleaned_data
        else:
            raise ValidationError('用户名或密码错误')
   
   #其他钩子
    def _post_clean(self):
        pass

from验证

urls.py

from django.contrib import admin
from django.urls import path
from django.conf.urls import url,include
#from app import views
from app.views import test
from app.views import account
urlpatterns = [
    #path('admin/', admin.site.urls),
    url(r'^index/',test.index),
    url(r'^login.html$',account.login),
]

####
index.py

from django.shortcuts import render
from app.forms import UserInfoForm
# Create your views here.

def index(request):
    if request.method == "GET":
        obj = UserInfoForm()
        #传递默认值
        #obj = UserInfoForm({'user':'alex'})
        return render(request,'index.html',{'obj':obj})

    elif request.method == "POST":
        obj = UserInfoForm(request.POST,request.FILES)
        obj.is_valid()


####
login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>login</title>
</head>
<body>
    <form id="fm">
        {% csrf_token %}
        <p><input type="text" name="username" /></p>
        <p><input type="text" name="password" /></p>
        <a id="submit">提交</a>
    </form>
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
        $(function(){
            $('$submit').click(function(){
                $.ajax({
                    url:'/login.html',
                    type: 'POST',
                    data: $('#fm').serialize(),
                    success: function(arg){
                        arg = JSON.parse(arg);
                        console.log(arg);
                    },
                    error: function(){

                    }
                })
            })
        })
    </script>
</body>
</html>

####
account.py

from django.forms import fields
from django.forms import widgets
from django import forms
from django.shortcuts import render,HttpResponse
class LoginFrom(forms.Form):
    username = fields.CharField()
    password = fields.CharField(
        max_length=64,
        min_length=12,
    )

###自定义jsnon 默认json只支持python类型
from django.core.exceptions import ValidationError
import json
class JsonCustomEncoder(json.JSONEncoder):
    def default(self,field):
        if isinstance(field,ValidationError):
            return {'code': field.code,'messages':field.message}
        else:
            return json.JSONEncoder.default(self,field)


def login(request):
    if request.method == 'GET':
        return render(request,'login.html')
    elif request.method == "POST":
        ret = {'status':True,'error':None,'date':None}
        obj = LoginFrom(request.POST)
        if obj.is_valid():
            print(obj.cleaned_data)
        else:
            ret['error'] = obj.error.as_data()
        result = json.dumps(ret,cls=JsonCustomEncoder)
        return HttpResponse(result)　　

自定义json

第一种
	from django.core import serializrs
	
	v = models.tb.objects.all()
	data = serializers.serialize("json",v)
	
第二种
	import json
	from datetime import date
	from datetime import datetime
	
	class JsonCustomEncoder(json.JSONEncoder):
		def default(self,field):
			if isinstance(field,datetime):
				return field.atrftime('%Y-%m-%d %H:%M:%s')
			elif isinstance(field,date):
				return field.strftime('%Y-%m-%d')
			else:
            	return json.JSONEncoder.default(self,field)
     v = models.tb.objects.values('id','name','ctime')
     v = list(v)
     v = json.dumps(v,cls=JsonCustomEncoder)
     
     
     #####################
     v = models.UserType.objects.values('id','name')
     v = list(v)
     return HttpResponse(json.dumps(v))

登录验证吗

if request,method == POST:
	if request.session['CheckCode'].upper() == request.POST.get('check_code').upper():
		pass
	else:
    	print('验证码错误')
return render(request,'login.html')    	

12，obj.is_valid()错误信息

from app01.forms import RegisterForm
from django.core.excptions import NON_FIELD_ERRORS
#NON_FIELD_ERRORS = __all__

obj = RegisterForm(request.POST)
if obj.is_valid():
	obj.cleand_data
else:
	obj.errros
	{
        "__all__": [],
        'user':[{'code':'required','message':'xxx'}],
        'pwd':[{'code':'required','message':'xxx'}],
	}

14，From验证

from.py

from django.core.exceptions import ValidationError
from django import forms
from django.forms import fields
from django.forms import widgets
from repository import models

class RegisterForm(forms.Form):
    username = fields.CharField(
        widget=widgets.TextInput(attrs={'class':'form-control','placeholder':'请输入用户名'}),
        error_messages={'required': '用户名不能为空', 'min_length': '用户名长度不能小于3', 'max_length': '用户名长度不能大于12'},
        max_length=12,
        min_length=3,
    )
    email = fields.EmailField(
        max_length=32,
        min_length=8,
        widget=widgets.TextInput(attrs={'class': 'form-control', 'placeholder': '请输入邮箱'}),
        error_messages={'required': 'mail不能为空', 'min_length': 'mail长度不能小于32', 'max_length': 'mail长度不能大于12'}

    )
    password = fields.CharField(
        max_length=32,
        min_length=3,
        widget=widgets.PasswordInput(attrs={'class': 'form-control', 'placeholder': '请输入密码'}),
        error_messages={'required': '密码不能为空', 'min_length': '密码长度不能小于3', 'max_length': '密码长度不能大于32'},
    )

    passwd = fields.CharField(
        max_length=32,
        min_length=3,
        widget=widgets.PasswordInput(attrs={'class': 'form-control', 'placeholder': '确认密码'}),
        error_messages={'required': '密码不能为空', 'min_length': '密码长度不能小于3', 'max_length': '密码长度不能大于32'},
    )

    check_code = fields.CharField(
        max_length=32,
        min_length=3,
        widget=widgets.PasswordInput(attrs={'class': 'form-control', 'placeholder': '请输入验证码'}),
        error_messages={'required': '验证不能为空', 'min_length': '验证码长度不能小于3', 'max_length': '验证码长度不能大于32'},
    )


    def clean_username(self):
        user = models.UserInfo.objects.filter(username=self.cleaned_data['username']).count()
        if user:
            raise ValidationError('用户名已经存在')

    def clean_email(self):
        user = models.UserInfo.objects.filter(email=self.cleaned_data['email']).count()
        if user:
            raise ValidationError('邮箱已经存在')


    def clean(self):
        if self.cleaned_data['password'] != self.cleaned_data['passwd']:
            raise ValidationError('两次密码输入不相同！')

account.py

#!/usr/bin/env python
# -*- coding:utf-8 -*-
from io import BytesIO
from django.shortcuts import HttpResponse
from django.shortcuts import render,redirect
from utils.check_code import create_validate_code
from repository import models,Froms
import re,json
from django.core.exceptions import ValidationError


def check_code(request):
    """
    验证码
    :param request:
    :return:
    """
    stream = BytesIO()
    img, code = create_validate_code()
    img.save(stream, 'PNG')
    request.session['CheckCode'] = code
    return HttpResponse(stream.getvalue())


def login(request):
    """
    登陆
    :param request:
    :return:
    """
    if request.method == "GET":
        return render(request, 'login.html')

    elif request.method == "POST":
        if request.session['CheckCode'].upper() == request.POST.get('check_code').upper():
            u = request.POST.get('username')
            p = request.POST.get('password')
            obj = models.UserInfo.objects.filter(username=u,password=p).first()
            if obj:
                request.session['username'] = u
                request.session['is_login'] = True
                return redirect('home.html')
                #return render(request, 'home.html')
            else:
                return HttpResponse('用户名或密码错误')

        else:
            print('验证码错误')
            return render(request, 'login.html')


def register(request):
    """
    注册
    :param request:
    :return:
    """
    ret = {'status': True, 'error': None, 'date': None}
    obj = Froms.RegisterForm()

    if request.method == "GET":
        return render(request, 'register.html',{'obj':obj})
    elif request.method == "POST":
        obj = Froms.RegisterForm(request.POST)
        u = request.POST.get('username')
        p = request.POST.get('password')
        e = request.POST.get('email')
        if obj.is_valid():
            models.UserInfo.objects.create(username=u,password=p,email=e)
            return redirect('/backend/base-info.html')
        else:
            ret['error'] = obj.errors.as_data()
            #print(ret['error']['username'])
            result = json.dumps(ret,cls=JsonCustomEncoder)
            test = json.loads(result)
            #print( test['error']['__all__'][0])
            return render(request,'register.html',{'fm':test,'obj':obj,'pwd':test['error']['__all__'][0]})
        # result = json.dumps(ret, cls=JsonCustomEncoder)
        # return HttpResponse(result,{'obj':obj})




def logout(request):
    """
    注销
    :param request:
    :return:
    """
    pass

def auth(func):
    def inner(request,*args,**kwargs):
        v = request.session.get('is_login',None)
        if not v:
            return render(request,'login.html')
        return func(request,*args,**kwargs)
    return inner

class JsonCustomEncoder(json.JSONEncoder):
    def default(self,field):
        if isinstance(field,ValidationError):
            return {'code': field.code,'messages': field.messages}
        else:
            return json.JSONEncoder.default(self,field)

models.py

from django.db import models


class UserInfo(models.Model):
    """
    用户表
    """
    nid = models.BigAutoField(primary_key=True)
    username = models.CharField(verbose_name='用户名', max_length=32, unique=True)
    password = models.CharField(verbose_name='密码', max_length=64)
    nickname = models.CharField(verbose_name='昵称', max_length=32)
    email = models.EmailField(verbose_name='邮箱', unique=True)
    avatar = models.ImageField(verbose_name='头像')

    create_time = models.DateTimeField(verbose_name='创建时间', auto_now_add=True)

    fans = models.ManyToManyField(verbose_name='粉丝们', to='UserInfo', through='UserFans',
                                  through_fields=('user', 'follower'))


class Blog(models.Model):
    """
    博客信息
    """
    nid = models.BigAutoField(primary_key=True)
    title = models.CharField(verbose_name='个人博客标题', max_length=64)
    site = models.CharField(verbose_name='个人博客前缀', max_length=32, unique=True)
    theme = models.CharField(verbose_name='博客主题', max_length=32)
    user = models.OneToOneField(to='UserInfo', to_field='nid',on_delete=models.CASCADE)


class UserFans(models.Model):
    """
    互粉关系表
    """
    user = models.ForeignKey(verbose_name='博主', to='UserInfo', to_field='nid', related_name='users',on_delete=models.CASCADE)
    follower = models.ForeignKey(verbose_name='粉丝', to='UserInfo', to_field='nid', related_name='followers',on_delete=models.CASCADE)

    class Meta:
        unique_together = [
            ('user', 'follower'),
        ]


class Category(models.Model):
    """
    博主个人文章分类表
    """
    nid = models.AutoField(primary_key=True)
    title = models.CharField(verbose_name='分类标题', max_length=32)

    blog = models.ForeignKey(verbose_name='所属博客', to='Blog', to_field='nid',on_delete=models.CASCADE)


class ArticleDetail(models.Model):
    """
    文章详细表
    """
    content = models.TextField(verbose_name='文章内容', )

    article = models.OneToOneField(verbose_name='所属文章', to='Article', to_field='nid',on_delete=models.CASCADE)


class UpDown(models.Model):
    """
    文章顶或踩
    """
    article = models.ForeignKey(verbose_name='文章', to='Article', to_field='nid',on_delete=models.CASCADE)
    user = models.ForeignKey(verbose_name='赞或踩用户', to='UserInfo', to_field='nid',on_delete=models.CASCADE)
    up = models.BooleanField(verbose_name='是否赞')

    class Meta:
        unique_together = [
            ('article', 'user'),
        ]


class Comment(models.Model):
    """
    评论表
    """
    nid = models.BigAutoField(primary_key=True)
    content = models.CharField(verbose_name='评论内容', max_length=255)
    create_time = models.DateTimeField(verbose_name='创建时间', auto_now_add=True)

    reply = models.ForeignKey(verbose_name='回复评论', to='self', related_name='back', null=True,on_delete=models.CASCADE)
    article = models.ForeignKey(verbose_name='评论文章', to='Article', to_field='nid',on_delete=models.CASCADE)
    user = models.ForeignKey(verbose_name='评论者', to='UserInfo', to_field='nid',on_delete=models.CASCADE)


class Tag(models.Model):
    nid = models.AutoField(primary_key=True)
    title = models.CharField(verbose_name='标签名称', max_length=32)
    blog = models.ForeignKey(verbose_name='所属博客', to='Blog', to_field='nid',on_delete=models.CASCADE)


class Article(models.Model):
    nid = models.BigAutoField(primary_key=True)
    title = models.CharField(verbose_name='文章标题', max_length=128)
    summary = models.CharField(verbose_name='文章简介', max_length=255)
    read_count = models.IntegerField(default=0)
    comment_count = models.IntegerField(default=0)
    up_count = models.IntegerField(default=0)
    down_count = models.IntegerField(default=0)
    create_time = models.DateTimeField(verbose_name='创建时间', auto_now_add=True)

    blog = models.ForeignKey(verbose_name='所属博客', to='Blog', to_field='nid',on_delete=models.CASCADE)
    category = models.ForeignKey(verbose_name='文章类型', to='Category', to_field='nid', null=True,on_delete=models.CASCADE)

    type_choices = [
        (1, "Python"),
        (2, "Linux"),
        (3, "OpenStack"),
        (4, "GoLang"),
    ]

    article_type = models.IntegerField(choices=type_choices, default=None)

    tags = models.ManyToManyField(
        to="Tag",
        through='Article2Tag',
        through_fields=('article', 'tag'),
    )


class Article2Tag(models.Model):
    article = models.ForeignKey(verbose_name='文章', to="Article", to_field='nid',on_delete=models.CASCADE)
    tag = models.ForeignKey(verbose_name='标签', to="Tag", to_field='nid',on_delete=models.CASCADE)

    class Meta:
        unique_together = [
            ('article', 'tag'),
        ]

index.html

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <link rel="stylesheet" href="/static/plugins/bootstrap/css/bootstrap.css"/>
    <link rel="stylesheet" href="/static/plugins/font-awesome/css/font-awesome.css"/>
    <link rel="stylesheet" href="/static/css/edmure.css"/>
    <link rel="stylesheet" href="/static/css/commons.css"/>
    <link rel="stylesheet" href="/static/css/account.css"/>
    <style>

    </style>
</head>
<body>
<div class="register">
    <div style="font-size: 25px; font-weight: bold;text-align: center;">
        用户注册
    </div>
    <form role="form" method="POST" id="fm">
        {% csrf_token %}
        <div class="form-group">
            <p>{{ obj.username }}</p>
            <span style="color:red">{{ fm.error.username.0 }}</span>
        </div>
        <div class="form-group">
            <p>{{ obj.email }}</p>
            <span style="color:red">{{ fm.error.email.0 }}</span>
        </div>
        <div class="form-group">
            <p>{{ obj.password }}</p>
{#            <span style="color:red">{{ pwd }}</span>#}
        </div>
        <div class="form-group">
            <p>{{ obj.passwd }}</p>
            <span style="color:red">{{ pwd }}</span>
        </div>
        <div class="form-group">
            <label for="password">验证码</label>

            <div class="row">
                <div class="col-xs-7">
                    <p>{{ obj.check_code }}</p>
                </div>
                <div class="col-xs-5">
                    <img src="/check_code.html">
                </div>
            </div>

        </div>
        <input type="submit" class="btn btn-default" value="下一步"/>

    </form>
</div>
<script src="/static/js/jquery-1.12.4.js"></script>
<script src="/static/js/jquery.cookie.js"></script>
{#<script src="/static/js/my.js"></script>#}
</body>
</html>