django补充和form组件

Posted 2020-10-13 —super—

Model常用操作：
- 参数：filter
- all,values,values_list

[obj(id,name,pwd,email),obj(id,name,pwd,email),]
models.UserInfo.objects.all()

[obj(id,name,email)] # pwd未取值
data_list = models.UserInfo.objects.all().only(‘name‘,‘email‘)

for item in data_list:
item.id
item.name

[obj(id,pwd)] # pwd未取值
data_list = models.UserInfo.objects.all().defer(‘name‘,‘email‘)

for item in data_list:
item.id
item.pwd
路由系统：

反向生成URL：
/index/ func name=a1
{% url "a1"}
reverse(‘x‘)

/index/(\d+)/ func name=a2
{% url "a2" 11 %}
reverse(‘x‘,args=(11,))

/index/(?P<nid>\d+)/ func name=a3
{% url "a2" nid=11 %}
reverse(‘x‘,kwargs={‘nid‘:11})

Django生命周期：
- wsgi
- wsgiref
- uwsgi

Http请求本质：
a1=123&a2=456

{a1:13}


今日概要：

1. 数据库设计
- 属性相同归类到一张表中
- 连表有性能消耗
- 连表设计：
class UserType(models.Model):
"""
用户类型表,个数经常变动
"""
title = models.CharField(max_length=32)

class UserInfo(models.Model):
"""
用户表：讲师和班主任
"""
username = models.CharField(max_length=32)
password = models.CharField(max_length=64)
email = models.CharField(max_length=32)
ut = models.ForeignKey(to="UserType")
- choices
# class UserInfo(models.Model):
# """
# 用户表
# """
# username = models.CharField(max_length=32)
# password = models.CharField(max_length=64)
# email = models.CharField(max_length=32)
#
# user_type_choices = (
# (1, ‘班主任‘),
# (2, ‘讲师‘),
# )
#
# user_type_id = models.IntegerField(choices=user_type_choices)
- 一张表中对同一个其他表做FK，M2M时，主要 related_name
- 注释

- 补充：
"""
ID Title
1 图片
2 挨踢1024
3 段子
"""
class NewsType(models.Model):
title = models.CharField(max_length=32)

"""
ID Title Summary News_Type
1 t.... 科技... 2
2 t.... 科技... 1
3 t.... 科技... 2

"""
class News(models.Model):
title = models.CharField(max_length=32)
summary = models.CharField(max_length=255)
news_type = models.ForeignKey(to="NewsType")

# 查看所有新闻
new_list = News.objects.all()
for row in new_list:
print(row.title,row.summary,row.news_type.title)

 

 

"""
ID Title Summary News_Type
1 t.... 科技... 2
2 t.... 科技... 1
3 t.... 科技... 2

"""
class News(models.Model):
title = models.CharField(max_length=32)
summary = models.CharField(max_length=255)

news_type_chices = (
(1,‘图片‘),
(2,‘挨踢1024‘),
(3,‘段子‘),
)
news_type = models.IntegerField(choices=news_type_chices)

# 查看所有新闻
new_list = News.objects.all()
for row in new_list:
print(row.title,row.summary, row.get_news_type_display() )

2. 登录
- 装饰器
- Django内置+自定义配置文件
3. 老师管理
- Form组件
- 创建类，继承Form
- 创建字段，字段=正则表达式； PS: 字段名称，required, error_messages = {required,invalid}
- form = MyForm(data=request.POST)
- form.is_valid()
- form.cleaned_data
- form.errors

Form组件
1. 用户请求数据验证
2. 自动生成错误信息
3. 打包用户提交正确信息
4. 错误：保留上次输入内容
5. 定制页面上显示的html标签
Django Form组件
1. 创建规则（类，字段）
class Foo:
username = xxx
password = xxx
email = xxx
2. 数据和规则进行匹配
form = Foo(data=xxx,initial=初始化)
form.is_valid()
form.cleaned_data
form.errors

class TeacherForm(Form):
    username = fields.CharField(
        required=True,
        error_messages={‘required‘:‘用户名不能为空‘},
        widget=widgets.TextInput(attrs={‘placeholder‘:‘用户名‘,‘class‘:‘form-control‘})
    ) # 不能为空
    password = fields.CharField(required=True,error_messages={‘required‘:‘密码不能为空‘}, widget=widgets.TextInput(attrs={‘placeholder‘:‘密码‘,‘class‘:‘form-control‘})) # 不能为空
    email = fields.EmailField(required=True,error_messages={‘required‘:‘邮箱不能为空‘,‘invalid‘:‘邮箱格式错误‘},widget=widgets.EmailInput(attrs={‘placeholder‘:‘邮箱‘,‘class‘:‘form-control‘}))   # 不能为空，且邮箱格式


@auth
def add_teacher(request):
    if request.method == ‘GET‘:
        form = TeacherForm()
        return render(request,‘add_teacher.html‘,{‘form‘:form})
    else:
        """
        1. 用户请求数据验证
        2. 自动生成错误信息
        3. 打包用户提交正确信息
        4. 错误：保留上次输入内容
        5. 定制页面上显示的HTML标签
        Django Form组件
        1. 创建规则（类，字段）
            class Foo:
                username = xxx
                password = xxx
                email = xxx
        2. 数据和规则进行匹配
        """
        form = TeacherForm(data=request.POST) # 数据和规则放置一起
        if form.is_valid():                       # 开始校验,并获取校验结果
            # print(‘执行成功‘,form.cleaned_data)          # 所有匹配成功，字典
            # {‘username‘: ‘asd‘, ‘password‘: ‘sdf‘, ‘email‘: ‘[email protected]‘,‘ut_id‘:1}
            form.cleaned_data[‘ut_id‘] = 1
            models.UserInfo.objects.create(**form.cleaned_data)
            return redirect(‘/teachers/‘)

        return render(request, ‘add_teacher.html‘,{‘form‘:form})

@auth
def edit_teacher(request,nid):
    obj = models.UserInfo.objects.filter(id=nid,ut_id=1).first()
    if not obj:
        return redirect(‘/teachers/‘)

    if request.method == "GET":
        # 显示input，并且将数据库中的默认值填写到input框中
        form = TeacherForm(initial={‘username‘:obj.username,‘password‘:obj.password,‘email‘:obj.email})
        return render(request,‘edit_teacher.html‘,{‘form‘:form})
    else:
        form = TeacherForm(data=request.POST)
        if form.is_valid():
            # 校验成功
            models.UserInfo.objects.filter(id=nid).update(**form.cleaned_data)
            return redirect(‘/teachers/‘)
        return render(request,‘edit_teacher.html‘,{‘form‘:form})


class TestForm(Form):
    caption = fields.CharField()
    # xxx = fields.ChoiceField(choices=[(1,‘讲师‘),(2,‘班主任‘)])
    # xxx = fields.ChoiceField(choices=models.UserInfo.objects.values_list(‘id‘,‘username‘))
    # xxx = fields.ChoiceField(choices=models.UserType.objects.values_list(‘id‘,‘title‘))
    xxx = fields.MultipleChoiceField(choices=models.UserInfo.objects.values_list(‘id‘,‘username‘))

def test(request):
    form = TestForm(initial={‘xxx‘:4})
    form = TestForm(initial={‘xxx‘:[1,2,3]})
    return render(request,‘test.html‘,{‘form‘:form})

试用