django系列筆記

時間 2020-07-05

標籤 django 系列筆記欄目 Python 简体版

原文原文鏈接

說明：本文環境windows+pycharm專業版html

1.HelloDjandopython

環境搭建：爲django項目建立本身獨立的python虛擬環境，並在pycharm中選擇解釋器爲剛剛建立的python虛擬環境mysql

進入到要建立django項目的目錄，執行以下命令sql

django-admin startproject HelloDjango  #建立項目
python manage.py startapp App    #建立應用，注意建立後先把該應用註冊到settings.py中，以避免後續忘記
python manage.py runserver　　#啓動服務

瀏覽器訪問：http://127.0.0.1:8000/ 可看到django的歡迎界面shell

2.MTV數據庫

模板配置：須要在項目目錄中建立templates文件夾並標記；須要在settings中進行註冊django

路由優化配置：拆分爲多個app；繼承拆分路由器windows

例子1：瀏覽器

瀏覽器訪問：http://127.0.0.1:8000/hello/app

例子2：

項目根目錄下建立文件夾templates（若是想讓代碼自動提示，須要右擊templates Mark Directory as Templates）

訪問： http://127.0.0.1:8000/home/ 可看到以下界面

3.model的介紹與簡單使用

Object Relational Mapping 對象關係映射

遷移的概念：就是將模型映射到數據庫的過程

編寫models.py後，執行以下命令：

python manage.py makemigrations  #生成遷移
python manage.py migrate   #執行遷移

如何使用mysql數據庫？（django默認的是sqlite3）

1.修改setting.py文件
2.安裝pymysql ，pip install pymysql（若是原來已安裝的話不須要安裝）
3.在 項目根目錄/HelloDjango/__init__.py增長以下內容：
import pymysql
pymysql.install_as_MySQLdb()

使用mysql數據庫

1.首先編寫應用下的models.py
from django.db import models

# Create your models here.
class Student(models.Model):
    s_name = models.CharField(max_length=16)
    s_age = models.IntegerField(default=1)

2.應用下新建urls.py並寫入以下代碼（注意鼠標定位到函數上就能夠使用快捷鍵alt+enter進行快速導包與建立view對應的函數）
from django.conf.urls import url

from Two import views




urlpatterns = [
    url(r'^index/',views.index),
    url(r'^addstudent/',views.add_student),
    url(r'^getstudents/',views.get_students),
    url(r'^updatestudent/',views.update_student),
    url(r'^deletestudent/',views.delete_student),
]

3.項目下的urls.py增長以下
url(r'^two/',include('Two.urls')),

4.編寫應用下的views.py
import random

from django.http import HttpResponse
from django.shortcuts import render

# Create your views here.
from Two.models import Student


def index(request):
    return HttpResponse("Two index")


def add_student(request):
    student = Student()
    student.s_name = 'Tom%d'%random.randrange(100)
    student.save()

    return HttpResponse("Add Success %s"%student.s_name)


def get_students(request):
    students = Student.objects.all()
    for student in students:
        print(student.s_name)
    context = {
        "hobby":"play",
        "students":students
    }
    return render(request,"student_list.html",context=context)


def update_student(request):
    student = Student.objects.get(pk= 2)
    student.s_name = 'pomelo'
    student.save()
    return HttpResponse("student update success")


def delete_student(request):
    student =  Student.objects.get(pk=3)
    student.delete()
    return HttpResponse("delete student success")

5.若是4中有些使用到了html，則須要在項目根目錄下的templates下建立對應的html文件
如：student_list.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>StudentList</title>
</head>
<body>
<h2>Ubuntu</h2>
<h3>{{ hobby }}</h3>
<h1>Student List</h1>
<hr>
<ul>
    {% for student in students %}
        <li>{{ student.s_name }}</li>
    {% endfor %}
</ul>
</body>
</html>

model的簡單使用一

render的原理，瞭解便可：

from django.http import HttpResponse
from django.shortcuts import render  # 實際上是個快捷鍵

# Create your views here.
from django.template import loader


def index(request):
    three_index  = loader.get_template('three_index.html')  # 獲取模板
    result = three_index.render()   # 渲染
    print(result)
    return HttpResponse(result)

View Code

4.model-數據常規操做、級聯數據

python manage.py shell：能夠用來調試數據

D:\django_project\day01\HelloDjango>python manage.py shell
Python 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 17:00:18) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from Two.models import Student
>>> students = Student.objects.all()
>>> students
<QuerySet [<Student: Student object (1)>, <Student: Student object (2)>, <Student: Student object (3)>, <Student: Student object (4)>, <Student: Student object (5)>, <Student: Student ob
ject (6)>, <Student: Student object (7)>]>
>>> for student in students:
...     print(student.s_name)
...
Tom8
Tom97
Tom2
Tom45
Tom16
Tom30
Tom28