Django實際應(yīng)用-投票程序（三）

IT那活兒發(fā)布于2023-01-11 13:20 / 1980人閱讀

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01

model模型

1.1 ORM架構(gòu)介紹

object :對象﹐對應(yīng)django模型中的class
Relationship:關(guān)系﹐對應(yīng)關(guān)系型數(shù)據(jù)庫
Mapping:映射
一個class對應(yīng)數(shù)據(jù)庫中的一張表
表中的字段與class中的類變量對應(yīng)
數(shù)據(jù)庫中的數(shù)據(jù)類型也與django模型中的類映射
表中的每個記錄都與class的實例對應(yīng)

1.2 編寫models.py

from django.db import models

# Create your models here.

class Question(models.Model):

question_text = models.CharField(max_length=200, unique=True)

pub_date = models.DateTimeField() #不加Field，沒有時分秒

class Chioce(models.Model):

chioce_text = models.CharField(max_length=200, unique=True)

votes = models.IntegerField(default=0)

question = models.ForeignKey(Question) #如果想要修改字段名，在配置文件中修改之后，重新生成表

1.3 生成表

python manage.py makemigrations

python manage.py migrate

1.4 將模型加入到后臺頁面

# polls/admin.py

from  django.contrib import  admin# 在當(dāng)前目錄下的models模塊中導(dǎo)入模型

from .models import   Question, Choice

# Register your models here.

admin.site.register(Question)

admin.site.register(Choice)

1.5 問題解決辦法

class Question(models.Model):

question_text = models.CharField(max_length=200, unique=True)

pub_date = models.DateTimeField()

def __str__(self):

return question:%s % self.question_text

class Chioce(models.Model):

chioce_text = models.CharField(max_length=200, unique=True)

votes = models.IntegerField(default=0)

question = models.ForeignKey(Question)

def __str__(self):

return %s:%s % return %s:%s % (self.question,self.chioce_text)

02

Django API（首頁）

2.1 在views文件中把問題取出來傳給html

# polls/views.py

from django.shortcuts import render

from .models import Question

def index(request):

  questions = Question.objects.order_by(-pub_date)

returnrender(request, index.html, {questions: questions})

2.2 編輯index.html



<htmllang="en">

<head>

<metacharset="UTF-8">

<title>投票首頁title>

head>

<body>

<div class="container">

<div class="content">

<h1>投票首頁h1>

<ol>

{% for question in questions %}

<li>

<a href="{% url a question.id %}" target="_blank">
#question_id是views.py中的d+這個參數(shù)，數(shù)據(jù)庫中沒有指定主鍵時Django會自動創(chuàng)建主鍵，question_id就是問題的id號

{{ question.question_text }}a>

     {{ question.pub_date }}

li>

{%endfor%}

ol>

div>

div>

body>

html>

2.3 可以添加輪播圖

<div class="container">

<div id="linux-carousel" class="carousel slide">

<ol class="carousel-indicators">

<li class="active" data-target="#linux-carousel" data-slide-to="0">li>  #輪播圖下面的小圓點

<li data-target="#linux-carousel" data-slide-to="1">li>

<li data-target="#linux-carousel" data-slide-to="2">li>

ol>

<div class="carousel-inner">

<div class="item active">

<a href="http://www.sogou.com" target="_blank">

<img src="{% static imgs/first.jpg %}">

a>

div>

<div class="item">

<img src="{% static imgs/second.jpg %}">

div>

<div class="item">

<img src="{% static imgs/third.jpg %}">

div>

div>

<a href="#linux-carousel" data-slide="prev" class="carousel-control left"> <span class="glyphicon glyphicon-chevron-left">span>    #向左翻



制作投票詳情頁

a>

<a href="#linux-carousel" data-slide="next" class="carousel-control right"> <span class="glyphicon glyphicon-chevron-right">span>   #向右翻

a>

div>

<script src="{% static js/jquery.min.js %}">script>    #要有JS代碼才能實現(xiàn)輪播圖

<script src="{% static js/bootstrap.min.js %}">script>

<script type="text/javascript">

2.4 模板繼承（為了避免一些網(wǎng)頁的重復(fù)代碼）

1）復(fù)制index.html一本命令為bak.html

# 在basic.html中，將個性（不相同）內(nèi)容用block替代

{% load static %}



<html lang="en">

<head><meta charset="UTF-8">

<title>{% block title %}{% endblock %}title>

<meta name="viewport" content="width=device-width, initial-scale=1">

<link rel="stylesheet" href="{% static css/bootstrap.min.css %}">

head>

<body>

<div class="container">

<div id="linux-carousel" class="carousel slide">

<ol class="carousel-indicators">

<li class="active" data-target="#linux-carousel" data-slide-to="0">li>

<li data-target="#linux-carousel" data-slide-to="1">li>

<li data-target="#linux-carousel" data-slide-to="2">li>

ol>

<div class="carousel-inner">

<div class="item active">

<a href="http://www.sogou.com" target="_blank">

<img src="{% static imgs/first.jpg %}">   #圖片放在polls下static目錄的imgs目錄中

a>

div>

<div class="item">

<img src="{% static imgs/second.jpg %}">

div>

<div class="item">

<img src="{% static imgs/third.jpg %}">

div>

div>

<a href="#linux-carousel" data-slide="prev" class="carousel-control left"> <span class="glyphicon glyphicon-chevron-left">span>



制作投票詳情頁 a>

<a href="#linux-carousel" data-slide="next" class="carousel-control right"> <span class="glyphicon glyphicon-chevron-right">span>

a>

div>

{% block content %}{% endblock %}

<script src="{% static js/jquery.min.js %}">script>

<script src="{% static js/bootstrap.min.js %}">script>

<script type="text/javascript">script>

body>

html>

2）index.html

# 修改index.html，把共性內(nèi)容刪除，個性內(nèi)容寫到對應(yīng)的block中

{% extends bak.html %} #繼承

{% load static %}

{% block title %}投票首頁{% endblock %}

{% block content %}

class="content h4">

class="text-center text-warning">投票首頁


"margin: 20px 0">

{% for question in questions %}

"{% url detail question.id %}" target="_blank">

{{ question.question_text }}  {{ question.pub_date }}

 {% endfor %}





{% endblock %}

03

制作a.html（次頁）

3.1 編輯views.py

from django.shortcuts import render

from .models import Question, Chioce

# Create your views here.

def index(request):

d = Question.objects.order_by(-pub_date)

return render(request,index.html,{d:d})

def a(request,question_id):

c = Question.objects.get(id=question_id)

return  render(request,a.html,{id:c})

def result(request,id):

return  render(request,result.html,{id:id})

3.2 編輯a.html（取出選項）

{% extends bak.html%}

{% load static %}

{% block title%}polls{%endblock%}

{% block content%}

<div class="container">

<h1>{{ id.id }}h1>

div>

<div class="content h4 text-warning"  >

<h1 class="text-center">chioceh1>

<h2>{{ id }}h2>

<form action="">
      {% csrf_token %} #安全選項

{% for i in id.chioce_set.all %}

<div class="radio">

<label >

<input type="radio" name="chioce_id" value="{{ chioce_id }}">

{{ i.chioce_text }}

label>

div>

{% endfor %}

form>

div>

<div class="group">

<input  class="btn btn-primary" tpye="submit" value="submit">

div>

{%endblock%}

04

實現(xiàn)投票功能

實現(xiàn)數(shù)據(jù)庫的增刪改查。執(zhí)行函數(shù)對model模型的操作（url-->views-->model）

4.1 配置urls.py

from django.conf.urls import url,include

from django.contrib import admin

from . import  views



urlpatterns = [

url(r^$, views.index,name=index),

url(r(d+)/$, views.a,name=a),

url(r(d+)/result/$, views.result,name=result),

url(r(d+)/vote/$, views.vote,name=vote),

]

4.2 配置views.py

from django.shortcuts import  render, redirect

from .models import Question, Chioce

# Create your views here.

def index(request):

d = Question.objects.order_by(-pub_date)

return render(request,index.html,{d:d})

def a(request,question_id):

c = Question.objects.get(id=question_id)

return  render(request,a.html,{id:c})

def result(request,id):

return  render(request,result.html,{id:id})

def vote(request,id):

d = Question.objects.get(id=id) #取出問題

# 當(dāng)用戶提交表單時，request.POST是一個字典，里面記錄了與POST相關(guān)的數(shù)據(jù)

# choice_id是detail.html頁面中單選按鈕的name，值是選項的id（value的值）

chioce_id = request.POST.get(chioce_id) #取出name的值

chioce = d.chioce_set.get(id=chioce_id) #取出對用id的項

chioce.votes += 1

chioce.save()

# 這里返回使用的不是render，因為render直接返回頁面，URL不變，也就是http://x.x.x.x/polls/2/vote顯示的是2號問題的投票結(jié)果，這是不合理的應(yīng)該由http://x.x.x.x/polls/2/result/顯示投票結(jié)果。所以使用redirect

return redirect(result,id)

4.3 配置a.html

{% extends bak.html%}

{% load static %}

{% block title%}polls{%endblock%}

{% block content%}

<div class="container">

<h1>{{ id.id }}h1>

div>

<div class="content h4 text-warning"  >

<h1 class="text-center">chioceh1>

<h2>{{ id }}h2>

<form action="{% url vote id.id %}" method="post">

{% csrf_token %}

{% for i in id.chioce_set.all %}

<div class="radio">

<label >

<input type="radio" name="chioce_id" value="{{ i.id }}">

{{ i.chioce_text }}

label>

div>

{% endfor %}

<div class="form-group">

<input  class="btn btn-primary" type="submit" value="submit">

div>

form>

div>



{%endblock%}

05

配置result.html

5.1 views.py

from django.shortcuts import  render, redirect

from .models import Question, Chioce

# Create your views here.

def index(request):

d = Question.objects.order_by(-pub_date)

return render(request,index.html,{d:d})

def a(request,question_id):

c = Question.objects.get(id=question_id)

return  render(request,a.html,{id:c})

def result(request,id):

d = Question.objects.get(id=id)

return  render(request,result.html,{id:d})

def vote(request,id):

d = Question.objects.get(id=id)

chioce_id = request.POST.get(chioce_id)

chioce = d.chioce_set.get(id=chioce_id)

chioce.votes += 1

chioce.save()

return redirect(result,id)

5.2 配置resul.html

{% extends bak.html%}

{% load static %}

{% block title%}投票結(jié)果{%endblock%}

{% block content%}

<div>

<h1 class="text-center">{{ id.id }}投票結(jié)果h1>

<table class="table table-striped table-hover">

<thead class="bg-primary">

<tr>

<td colspan="2">{{ id.question_text }}td>

tr>

thead>

{% for i in id.chioce_set.all %}

<tr>

<td>{{ i.chioce_text }}td>

<td >{{ i.votes }}td>

tr>

{%endfor%}

table>



div>

{%endblock%}