python基础(二十)
1、Django请求的生命周期
路由系统 -> 试图函数(获取模板+数据=》渲染) -> 字符串返回给用户
2、路由系统
/index/ -> 函数或类.as_view()
/detail/(\d+) -> 函数(参数) 或 类.as_view()(参数)
/detail/(?P<nid>\d+) -> 函数(参数) 或 类.as_view()(参数)
/detail/ -> include("app01.urls")
/detail/ name='a1' -> include("app01.urls")
- 视图中:reverse
- 模板中:{% url "a1" %}
3、视图
FBV:函数
def index(request,*args,**kwargs):
..
CBV:类
class Home(views.View):
def get(self,reqeust,*args,**kwargs):
..
获取用户请求中的数据:
request.POST.get
request.GET.get
reqeust.FILES.get()
# checkbox,
........getlist()
request.path_info
文件对象 = reqeust.FILES.get()
文件对象.name
文件对象.size
文件对象.chunks()
# <form 特殊的设置></form>
给用户返回数据:
render(request, "模板的文件的路径", {'k1': [1,2,3,4],"k2": {'name': '张扬','age': 73}})
redirect("URL")
HttpResponse(字符串)
4、模板语言 render(request, "模板的文件的路径", {'obj': 1234, 'k1': [1,2,3,4],"k2": {'name': '张扬','age': 73}})
<html>
<body> <h1> {{ obj }} </h1> <h1> {{ k1.3 }} </h1> <h1> {{ k2.name }} </h1> {% for i in k1 %} <p> {{ i }} </p> {% endfor %}
{% for row in k2.keys %} {{ row }} {% endfor %}
{% for row in k2.values %} {{ row }} {% endfor %}
{% for k,v in k2.items %} {{ k }} - {{v}} {% endfor %}
</body> </html>
5、ORM a. 创建类和字段 class User(models.Model): age = models.IntergerFiled() name = models.CharField(max_length=10)#字符长度
Python manage.py makemigrations python manage.py migrate
# settings.py 注册APP
b. 操作 增 models.User.objects.create(name='qianxiaohu',age=18) dic = {'name': 'xx', 'age': 19} models.User.objects.create(**dic)
obj = models.User(name='qianxiaohu',age=18) obj.save() 删 models.User.objects.filter(id=1).delete() 改 models.User.objects.filter(id__gt=1).update(name='alex',age=84) dic = {'name': 'xx', 'age': 19} models.User.objects.filter(id__gt=1).update(**dic) 查 models.User.objects.filter(id=1,name='root') models.User.objects.filter(id__gt=1,name='root') models.User.objects.filter(id__lt=1) models.User.objects.filter(id__gte=1) models.User.objects.filter(id__lte=1)
models.User.objects.filter(id=1,name='root') dic = {'name': 'xx', 'age__gt': 19} models.User.objects.filter(**dic)
v1 = models.Business.objects.all() # QuerySet ,内部元素都是对象 # QuerySet ,内部元素都是字典
v2 = models.Business.objects.all().values('id','caption') # QuerySet ,内部元素都是元组
v3 = models.Business.objects.all().values_list('id','caption') # 获取到的一个对象,如果不存在就报错 models.Business.objects.get(id=1) 对象或者None = models.Business.objects.filter(id=1).first()
外键: v = models.Host.objects.filter(nid__gt=0) v[0].b.caption ----> 通过.进行跨表
外键: class UserType(models.Model): caption = models.CharField(max_length=32) id caption # 1,普通用户 # 2,VIP用户 # 3, 游客
class User(models.Model): age = models.IntergerFiled() name = models.CharField(max_length=10)#字符长度 # user_type_id = models.IntergerFiled() # 约束, user_type = models.ForeignKey("UserType",to_field='id') # 约束,
name age user_type_id # aa 18 3 # bb 18 2 # cc 18 2
position:fixed absolute relative
Ajax
$.ajax({ url: '/host', type: "POST", data: {'k1': 123,'k2': "root"}, success: function(data){ // data是服务器端返回的字符串 var obj = JSON.parse(data); } })
建议:永远让服务器端返回一个字典
return HttpResponse(json.dumps(字典))
多对多: 创建多对多: 方式一:自定义关系表 class Host(models.Model): nid = models.AutoField(primary_key=True) hostname = models.CharField(max_length=32,db_index=True) ip = models.GenericIPAddressField(protocol="ipv4",db_index=True) port = models.IntegerField() b = models.ForeignKey(to="Business", to_field='id') # 10 class Application(models.Model): name = models.CharField(max_length=32) # 2
class HostToApp(models.Model): hobj = models.ForeignKey(to='Host',to_field='nid') aobj = models.ForeignKey(to='Application',to_field='id')
# HostToApp.objects.create(hobj_id=1,aobj_id=2)
方式二:自动创建关系表 class Host(models.Model): nid = models.AutoField(primary_key=True) hostname = models.CharField(max_length=32,db_index=True) ip = models.GenericIPAddressField(protocol="ipv4",db_index=True) port = models.IntegerField() b = models.ForeignKey(to="Business", to_field='id') # 10 class Application(models.Model): name = models.CharField(max_length=32) r = models.ManyToManyField("Host")
无法直接对第三张表进行操作
obj = Application.objects.get(id=1) obj.name
# 第三张表操作 obj.r.add(1) obj.r.add(2) obj.r.add(2,3,4) obj.r.add(*[1,2,3,4])
obj.r.remove(1) obj.r.remove(2,4) obj.r.remove(*[1,2,3])
obj.r.clear()
obj.r.set([3,5,7])
# 所有相关的主机对象“列表” QuerySet obj.r.all()