安裝：pip install Django==3.2.25
卸載：pip uninstall Django

django-admin startproject 項(xiàng)目名稱

urlpatterns = [
    path('login/', login),
]
def login(request):
    print("訪問到了登錄函數(shù)")
    return render(request,"login.html")

STATIC_URL = "/static/"
STATICFILES_DIRS = [
    os.path.join(BASE_DIR, 'static')
]

def page(request):
    return render(request, "main.html")
urlpatterns = [
    path("login/", login),
    path("login_action/", login_action),
    path("page/", page),
]

def main(request):
    return render(request, "main.html")
def page(request):
    return redirect("/main/")
urlpatterns = [
    path("login/", login),
    path("login_action/", login_action),
    path("page/", page),
    path("main/", main),
]

轉(zhuǎn)發(fā)(Forward)和重定向(Redirect)的核心區(qū)別在于：轉(zhuǎn)發(fā)是服務(wù)器內(nèi)部行為，一次請(qǐng)求且地址欄不變；重定向是客戶端行為，兩次請(qǐng)求且地址欄變化。
?核心機(jī)制差異?
    ?行為主體?。
        ?轉(zhuǎn)發(fā)?：由服務(wù)器內(nèi)部完成（如通過RequestDispatcher），客戶端無感知
        ?重定向?：服務(wù)器返回狀態(tài)碼（如302）和新URL，客戶端重新發(fā)起請(qǐng)求
    ?請(qǐng)求次數(shù)與效率?。
        ?轉(zhuǎn)發(fā)?：僅一次請(qǐng)求，性能更高
        ?重定向?：兩次獨(dú)立請(qǐng)求，效率較低
?功能特性對(duì)比?
    ?地址欄變化?。
        ?轉(zhuǎn)發(fā)?：地址欄顯示原始URL
        ?重定向?：地址欄更新為新URL
    ?數(shù)據(jù)共享能力?。
        ?轉(zhuǎn)發(fā)?：通過request.setAttribute()共享數(shù)據(jù)
        ?重定向?：需依賴Session或URL參數(shù)傳遞數(shù)據(jù)
    ?應(yīng)用范圍限制?。
        ?轉(zhuǎn)發(fā)?：僅限同一Web應(yīng)用內(nèi)資源
        ?重定向?：可跨應(yīng)用或訪問外部資源

python manage.py startapp app

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': "spt2505", # 數(shù)據(jù)庫名稱
        "HOST":"127.0.0.1", # 數(shù)據(jù)庫所在IP地址
        "PORT":3306, # 數(shù)據(jù)庫端口號(hào)
        "USER":"root", # 用戶名
        "PASSWORD":"root" # 密碼
    }
}

import pymysql
pymysql.install_as_MySQLdb()

class User(models.Model):
    id = models.AutoField(primary_key=True)
    username = models.CharField(max_length=20)
    password = models.CharField(max_length=20)

python manage.py makemigrations
python manage.py migrate

報(bào)錯(cuò)備注：
Django版本與MySQL 5.5的兼容性?：
Django與MySQL的版本兼容性如下：
    ?Django 2.0及以上版本支持MySQL 5.5及以上版本?。
    ?Django 2.2及以上版本支持MySQL 5.5、5.6和5.7版本?。
    ?Django 3.0及以上版本支持MySQL 5.6、5.7和8.0版本??。
因此，?Django 4.2版本不再支持MySQL 5.5?，因?yàn)镈jango 4.2官方不再支持MySQL 5.5，這會(huì)導(dǎo)致不兼容問題?。
解決方案
    ?降低Django版本?：可以將Django版本降級(jí)到3.2.18或更早的版本，以繼續(xù)使用MySQL 5.5?2。
    ?升級(jí)MySQL版本?：將MySQL升級(jí)到8.0或更高版本，以兼容Django 4.2?2
Django3.2版本與mysql5.5版本不兼容問題：
解決方式一：降低Django版本
解決方式二：升級(jí)Mysql版本
解決方式三：在settings.py文件追加兼容性配置
# 設(shè)置兼容
from django.db.backends.mysql.base import DatabaseWrapper
DatabaseWrapper.data_types['DateTimeField'] = 'datetime'

from django.shortcuts import render,redirect
from app.models import User
# Create your views here.
?
def login(request):
    # print("訪問到了登錄函數(shù)")
    return render(request,"login.html")
?
def login_action(request):
    print("登錄動(dòng)作")
    # 接收界面參數(shù)
    username = request.POST.get("username")
    password = request.POST.get("password")
?
    if User.objects.filter(username=username,password=password):
        #登錄成功
        return redirect("/main/")
    else:
        return render(request, "login.html",{"msg":"用戶名或密碼錯(cuò)誤！"})
?
def main(request):
    return render(request, "main.html")

from django.urls import path
from app import views
urlpatterns = [
    path("login/", views.login),
    path("login_action/", views.login_action),
    path("main/", views.main),
]

"""
    get方式：
        01：刷新瀏覽器地址欄
        02：a鏈接 href屬性
        03：window.location.href
        04：form表單中，method="GET"
        05：ajax請(qǐng)求中，type:"GET"
    post方式：
        01：form表單中，method="POST"
        02：ajax請(qǐng)求中，type:"POST"
"""
def requestTest(request):
    # print(request)
    # print(type(request))
    # print(request.method) # 得到請(qǐng)求方法   GET  POST   PUT  DELETE
    # print(request.GET.get("id")) # 接收前臺(tái)參數(shù)
    # print(request.FILES.get("filename"))  # 接收前臺(tái)文件
    # 了解
    # print(request.path)  # 獲取請(qǐng)求路由
    # print(request.path_info)  # 獲取請(qǐng)求路由
    # print(request.encoding) # 編碼
    # print(request.scheme)  # 請(qǐng)求協(xié)議
    # print(request.body)  # 請(qǐng)求體
    # print(request.get_port())  # 8000
    # print(request.get_host())  #localhost:8000
    # print(request.is_ajax()) # 當(dāng)次請(qǐng)求是否是ajax
    return HttpResponse("lufei,海賊王,21")

"""
    01:轉(zhuǎn)發(fā)render或重定向redirect
    02:直接通過HttpResponse響應(yīng)普通字符串
    03:在02響應(yīng)的基礎(chǔ)之上，如果字符串有特殊格式（JSON格式），那么響應(yīng)回去的數(shù)據(jù)可以做特殊處理
        響應(yīng)JSON格式字符串
            方式一：手動(dòng)拼接
            方式二：通過json模塊將字典轉(zhuǎn)換為json格式字符串 （需要導(dǎo)入： import json）
            方式三：通過JsonResponse  （需要導(dǎo)入：from django.http import JsonResponse）
"""
import json
from django.http import JsonResponse
def responseTest(request):
    #name = "{\"username\":\"lufei\",\"title\":\"海賊王\",\"age\":21}"
    name = {"username":"張三","password":"123456","address":"太原"}
    # return HttpResponse(json.dumps(name))
    return JsonResponse(name)

admin.site.register(models.User)

python manage.py createsuperuser

import os
if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "DjangoORM20250807.settings")
    import django
    django.setup()
    from app.models import User
    user = User.objects.get(id=1)
    print(user.username)

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'console':{
        'level':'DEBUG',
        'class':'logging.StreamHandler',
        },
    },

    'loggers': {
    'django.db.backends': {
        'handlers': ['console'],
        'propagate': True,
        'level':'DEBUG',
        },
    }
}

userlist = User.objects.all() print(userlist)

user = User.objects.get(username="喬巴43324") print(user)

user = User.objects.filter(username="路飛123") print(user)

userlist = User.objects.all().values("id","username") print(userlist)

userlist = User.objects.all().values_list("id", "username") print(userlist)

userlist = User.objects.exclude(id=2) print(userlist)

userlist = User.objects.order_by("sal","-id") print(userlist)

userlist = User.objects.order_by("-id").reverse() print(userlist)

userlist = User.objects.all().count() print(userlist)

userlist = User.objects.all().last() print(userlist)

userlist = User.objects.filter(id=2).exists() print(userlist)

userlist = User.objects.filter(id__gt=1,id__lte=3)
userlist = User.objects.filter(id__range=[1,3])
userlist = User.objects.filter(id__in=[1,3])
userlist = User.objects.filter(username__contains="LU")
print(userlist)

import os
if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "DjangoORM20250807.settings")
    import django
    django.setup()
    from app.models import Book, Press, BookType
    from django.db.models import F,Q
    #select * from app_book where sale > kucun
    #booklist = Book.objects.filter(sale__gte=F("kucun"))
    #print(booklist)
    #id 1,3   range   in
    bookes = Book.objects.filter(Q(id__gte=3) | Q(id__lte=1))
    print(bookes)vvv

import os
if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "DjangoORM20250807.settings")
    import django
    django.setup()
    from app.models import Book, Press, BookType
    from django.db.models import F,Q,Max,Min,Sum,Count,Avg
    #查詢圖書中價(jià)格的最大值和最小值
    # books = Book.objects.aggregate(Avg("bookprice"),Min("bookprice"))
    # print(books)
    # 分組 (默認(rèn)分組)
    # books = Book.objects.annotate(Count("bookprice"))
    # print(books)
    result = Book.objects.values("press_id").annotate(num = Count("id")).values("press_id","num")
    print(result)

import os
if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "DjangoORM20250807.settings")
    import django
    django.setup()
    from app.models import Book, Press, BookType

book = Book.objects.get(id=2)
print(book)
print(book.press.pressname)

booklist = Book.objects.filter(press_id=1)
print(booklist)

presslist = Press.objects.get(pressname="清華大學(xué)出版社").id
print(presslist)

#select * from app_book where press_id = (select id from app_press where pressname = "清華大學(xué)出版社")
booklist = Book.objects.filter(press_id=Press.objects.get(pressname__contains="人民").id)
print(booklist)

booklist = Book.objects.filter(press__pressname__contains="清華")
print(booklist)

booklist = Book.objects.all().values("bookname","press__pressname") 
print(booklist)

press = models.ForeignKey(to="Press",related_name="books",
press = Press.objects.get(pressname="清華大學(xué)出版社")
print(press)
print(press.book_set.all())
press = Press.objects.get(books__bookname="鹿鼎記")
print(press)

import os
if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "DjangoORM20250807.settings")
    import django
    django.setup()
    from app.models import Book, Press, BookType
    #booktype = BookType.objects.get(id=1)
    #print(booktype)
    # 設(shè)置多對(duì)多關(guān)系
    #booktype.books.set([1,2,3])
    # 通過圖書類型查找圖書
    # booktype = BookType.objects.get(id=1)
    # print(booktype.books.all())
    # 通過圖書查找圖書類型
    # 方式一
    # 方式二
    # book = Book.objects.get(id=2)
    # print(book.booktype_set.all())
    book = Book.objects.filter(booktypes__id=1)
    print(book)

反射：
    getattr()   setattr()  hasattr()  delattr()
    01：操作類屬性和類方法、靜態(tài)方法
        獲取屬性：getattr(類名,"屬性名稱字符串")
        設(shè)置屬性：setattr(類名,"屬性名稱字符串",需要設(shè)置的新的值)
        獲取方法：getattr(類名,"方法名稱字符串")
        執(zhí)行方法：getattr(類名,"方法名稱字符串")()
    02：操作對(duì)象屬性和對(duì)象方法
        獲取屬性：getattr(對(duì)象名稱,"屬性名稱字符串")
        執(zhí)行方法：getattr(對(duì)象名稱,"方法名稱字符串")(參數(shù))
    03：操作第三方模塊
        執(zhí)行方法：getattr(模塊名稱,"方法名稱字符串")(參數(shù))
    04：自己的模塊
        執(zhí)行方法：getattr(sys.modules["__main__"],"方法名稱字符串")(參數(shù))