第八章

Posted hanwei999

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  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

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‘}],
	}

  

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