实用技巧(掉进去又爬出来的坑儿)

2     # mysql数据库(不同的数据库会有迁移问题)

3     # Goods:模型类

4     # productnum:销量

5     # extra：一个Django的拓展查询方法，参数select是个字典

6     goods = Goods.objects.extra(select={‘p‘: ‘productnum+0‘})

7     goods = goods.extra(order_by=["p"])  # -p则为倒序

8

9     # 相当于sql语句

10 SELECT *,productnum+0 AS p FROM goods ORDER BY p

2     type: "POST",

3     url: "/accountAjax/",  // 此处一定要两侧都加/

4     dataType: "json",

5     data: JSON.stringify({"account_str": account_str}),  //这里是坑:以json的形式提交

6     success: function(data){

7         if(data.infos == "error"){

8             occupied_err.style.display = "block";

9         }

10     }

11 })

2     if request.method == "POST":

3         # 这里同样要以json的形式接受

4         # decode():将数据从二进制解码为json字符串

5         # json.loads():将数据还原为字典,再取其中的值就可以了

6         account = json.loads(request.body.decode())["account_str"]

7         try:

8             User.objects.get(userAccount=account)

9             return JsonResponse({"infos": "error"})

10         except User.DoesNotExist:

11             return JsonResponse({"infos": ""})

function getCookie(name) {

var cookieValue = null;

if (document.cookie && document.cookie != ‘‘) {

var cookies = document.cookie.split(‘;‘);

for (var i = 0; i < cookies.length; i++) {

var cookie = jQuery.trim(cookies[i]);

// Does this cookie string begin with the name we want?

if (cookie.substring(0, name.length + 1) == (name + ‘=‘)) {

cookieValue = decodeURIComponent(cookie.substring(name.length + 1));

break;

}

}

}

return cookieValue;

}

function sameOrigin(url) {

// url could be relative or scheme relative or absolute

var host = document.location.host; // host + port

var protocol = document.location.protocol;

var sr_origin = ‘//‘ + host;

var origin = protocol + sr_origin;

// Allow absolute or scheme relative URLs to same origin

return (url == origin || url.slice(0, origin.length + 1) == origin + ‘/‘) ||

(url == sr_origin || url.slice(0, sr_origin.length + 1) == sr_origin + ‘/‘) ||

// or any other URL that isn‘t scheme relative or absolute i.e relative.

!(/^(\/\/|http:|https:).*/.test(url));

}

function safeMethod(method) {

return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));

}

if (!safeMethod(settings.type) && sameOrigin(settings.url)) {

xhr.setRequestHeader("X-CSRFToken", getCookie(‘csrftoken‘));

}

});

STATIC_URL = ‘/static/‘

STATICFILES_DIRS = [os.path.join(BASE_DIR, ‘static‘)]

# 而这两个是显示媒体文件必须要设置的,原理和静态文件是一样的

MEDIA_URL = ‘/media/‘

MEDIA_ROOT = os.path.join(BASE_DIR, ‘media‘)

from django.conf import settings

from django.views.static import serve  # 相当于处理媒体文件的一个函数

urlpatterns = [

......

url(r‘^media/(.*)‘, serve, {"document_root": settings.MEDIA_ROOT}),

]

<!-- 也可以是{{ user.avatar.url }} 也就是：表名.字段名.url -->

<span><img src="/media/{{ userImg }}"></span>

# new_add_attr是User模型类中没有定义的属性,

# 可以通过这种方式给user设定一个新属性,用于后续的局部操作,但数据库中并没变

user = User.objects.get(username=username)

user.new_add_attr = 10

# 也可以用create(),但存密码时调用django.contrib.auth.hashers.make_password()

user = User.objects.create_user(username=username, password=password, email=email)

from django.core import serializers

json_data = serializers.serialize(‘json‘, goods)

return JsonResponse(json_data, safe=False)

from django.db.models.signals import post_save

from django.dispatch import receiver

from django.contrib.auth import get_user_model

UserProfile = get_user_model()

@receiver(post_save, sender=UserProfile)

def create_user(sender, instance=None, created=False, **kwargs):

if created:

instance.set_password(instance.password)

instance.save()

# __init__.py

default_app_config = ‘users.apps.UsersConfig‘

# apps.py

class UsersConfig(AppConfig):

name = ‘users‘

def ready(self):

import users.signals