Part 1：【 to encounter Django】—— （ One ） Create project
Part 2：【 to encounter Django】—— （ Two ） Database configuration
️ Part 3：【 to encounter Django】—— （ 3、 ... and ） View
️ Part 4：【 to encounter Django】—— （ Four ） Forms and common views
️ Part 5：【 to encounter Django】—— （ 5、 ... and ） Perfect interface （ Customize interfaces and styles ）
️ Part 6：【 to encounter Django】—— （ 6、 ... and ） User defined management interface
️ Part 7：【 to encounter Django】—— （ 7、 ... and ） automated testing
This series of articles , stay Django Under the basic template of the official document tutorial , Some improvements and deletions have been made , Added some of my own insights .
I hope that after reading this series of articles , Yes Django Be able to have a clear understanding .
It's a long way to go , I will go up and down ！
Django Official documents ：https://www.djangoproject.com/
Learning process , Read more official documents , Can solve many problems
This tutorial USES
poetryManage the project environment .
relevantpoetryInstallation and use of , Please refer to 【Python - A virtual environment 】 The start of the project , Start by isolating the development environment - CoderChaos - Blog Garden (cnblogs.com)
settings.pymysite/settings.py , It's a that includes Django Project settings Python modular .
Configuration of database , It's the variables DATABASES.
Django By default SQLite As the default database .Python built-in SQLite, So you don't need to install extra things to use .
If you do a real project , Better not to use SQLite.
# Django By default SQLite
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': BASE_DIR / 'db.sqlite3',
}
}
# Django Use MySQL To configure
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'mysite', # Use MySQL when , Need to be ahead of time MySQL establish mysite database
'HOST': '127.0.0.1',
'PORT': 3306,
'USER': 'root',
'PASSWORD': '******'
}
}
Parameter description ：
default：Django When connecting to the database , Default link default Database under .ENGINE： There are multiple options django.db.backends.sqlite3django.db.backends.postgresqldjango.db.backends.mysqldjango.db.backends.oracleNAME： Database name . If you use SQLite, The database will be a file on the computer . The default value is BASE_DIR / 'db.sqlite3', The database will be stored in the root directory of the project .SQLite, You must add some additional settings , such as USER、PASSWORD、HOST wait . Reference documents Be careful ： If you use
SQLiteOther databases , You need to make sure that you have created the database before using it . You can use it in your database interactive command lineCREATE DATABASE database_name;To complete the creation of the database .
Can be in settings.py In file , Modify time zone and language .
# Language
LANGUAGE_CODE = "zh-hans"
# The time zone
TIME_ZONE = "Asia/Shanghai"
Django The default self-contained application profile settings.py Some notes in the document ：INSTALLED_APPS
INSTALLED_APPS The default includes the following Django Built in application of ：
django.contrib.admin： Administrator site django.contrib.auth： Authentication and authorization system django.contrib.contenttypes： Content type framework django.contrib.sessions： Conversational framework django.contrib.messages： Message frame django.contrib.staticfiles： Framework for managing static files Some applications opened by default need at least one data table , therefore , Before using them, you need to create some tables in the database . The following commands need to be executed ：python manage.py migrate
Defining models , That is, database structure design and additional metadata .
In this voting application , You need to create two models ： problem Question And options Choice.
Question The model includes problem description and release time .Choice The model includes the option description and the current number of votes . Each option belongs to a question .# polls/models.py
from django.db import models
class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField(" Release date ")
class Choice(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
Creating models , Inherit django.db.models.Model; Each model has many class variables , Both represent a data table field in the model .
Each field is Field Class .
explain ：
Django You can create database tables for applications （CREATE TABLE）Django Can be created with Question and Choice Objects interact Python database APIDjango The application is “ Pluggable ” Of .
add to polls application
# mysite/settings.py
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'polls',
# or 'polls.apps.PollsConfig',
]
Now? ,Django The project already contains polls application .
Run the command makemigrations, Perform a migration ：python manage.py makemigrations
function makemigrations command ,Django It will detect the modification of the model file , And store the modified part as a migration . Migration is Django A storage of data structure changes .
migrate Is a command that automatically performs database migration and synchronously manages the database structure .
therefore , perform makemigrations after , To modify the synchronization in the database , Need to execute again python manage.py migrate.
Migration is a very powerful feature , It can continuously change the database structure during the development process without deleting tables and recreating tables .
It focuses on smooth database upgrade without data loss .
Changing the model requires the following steps ：
models.py file , Change the model python manage.py makemigrateions Generate migration files for model changes python manage.py migrate Application database migration Django Basic use of interactive commands Get into Django Interactive command line ：python manage.py shell
>>> from polls.models import Choice, Question
# See the table Question Table data
>>> Question.objects.all()
<QuerySet []> # There's no data right now
>>> from django.utils import timezone
# Create a Question Data objects
>>> q = Question(question_text="What's new?", pub_date=timezone.now())
# Store data objects to the database
>>> q.save()
# see q Object properties
>>> q.id
1
>>> q.question_text
"What's' new?"
>>> q.pub_date
datetime.datetime(2022, 3, 20, 11, 29, 15, 780052, tzinfo=datetime.timezone.utc)
# modify q Object properties
>>> q.question_text = "What's up?"
>>> q.save()
# Look again Question Table data
>>> Question.objects.all()
<QuerySet [<Question: Question object (1)>]>
about Question Returned display data , You can edit Question Modify the model code , to Question and Chioce increase __str__() Method .
class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField(" Release date ")
def __str__(self):
return self.question_text
class Choice(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
def __str__(self):
return self.choice_text
Once again into the Django Interactive command line ：python manage.py shell
Question.objects.all()
<QuerySet [<Question: What's up?>]>
import datetime
from django.db import models
from django.utils import timezone
class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField(" Release date ")
def __str__(self):
return self.question_text
def was_published_recently(self):
return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
class Choice(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
def __str__(self):
return self.choice_text
Once again into the Django Interactive command line ：python manage.py shell
>>> from polls.models import Question, Choice
# see __str__() Whether it is in effect
>>> Question.objects.all()
<QuerySet [<Question: What's up?>]>
# Django database API：filter
>>> Question.objects.filter(id=1)
<QuerySet [<Question: What's up?>]>
>>> from django.utils import timezone
>>> current_year = timezone.now().year
>>> Question.objects.get(pub_date__year=current_year)
<Question: What's up?>
# If there is no data in the database , An exception will be thrown
>>> Question.objects.get(id=2)
Traceback (most recent call last):
File "<input>", line 1, in <module>
File "D:\Codes\media\django\code001\venv\lib\site-packages\django\db\models\manager.py", line 85, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "D:\Codes\media\django\code001\venv\lib\site-packages\django\db\models\query.py", line 496, in get
raise self.model.DoesNotExist(
polls.models.Question.DoesNotExist: Question matching query does not exist.
# Get data object through primary key
>>> Question.objects.get(pk=1)
<Question: What's up?>
>>> q = Question.objects.get(pk=1)
# Use models.py Custom methods in
>>> q.was_published_recently()
True
# see q object , The object corresponding to the foreign key
>>> q.choice_set.all()
<QuerySet []>
# to q Object to add foreign key elements
>>> q.choice_set.create(choice_text="Not much", votes=0)
<Choice: Not much>
>>> q.choice_set.create(choice_text="The sky", votes=0)
<Choice: The sky>
>>> c = q.choice_set.create(choice_text="Just hacking again", votes=0)
# see c Elements （Choice object ）
>>> c
<Choice: Just hacking again>
# see c Attribute of element
>>> c.question
<Question: What's up?>
# see q object , The object corresponding to the foreign key
>>> q.choice_set.all()
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>
>>> q.choice_set.count()
3
>>> Choice.objects.filter(question__pub_date__year=current_year)
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>
>>> c = q.choice_set.filter(choice_text__startswith="Just hacking")
# Delete c object
>>> c.delete()
(1, {'polls.Choice': 1})
>>> q.choice_set.all()
<QuerySet [<Choice: Not much>, <Choice: The sky>]>
Djaong Management interface The management interface is not for visitors to the website , But for managers .
Run the following command on the command line ：python manage.py createsuperuser
You will be prompted later , enter one user name 、 mailbox 、 password 、 Confirm the password .
> python manage.py createsuperuser
user name (leave blank to use 'administrator'): admin
E-mail address : [email protected]
Password: ******
Password (again): ******
The password length is too short . The password must contain at least 8 Characters .
This password is so common .
The password contains only numbers .
Bypass password validation and create user anyway? [y/N]: y
Superuser created successfully.
Start development server ：python manage.py runserver
Open the browser ：http://127.0.0.1:8000/admin/
Enter your account and password , You can enter the management interface .
# polls/admin.py
from django.contrib import admin
from .models import Question
admin.site.register(Question)
Click the button in the page , You can use the add / delete / modify query function .
PyCharm Use tips 】PyCharm Tools for running makemigrations & migrate
PyCharm function django shell stay PyCharm Bottom toolbar , choice Python Console You can enter python manage.py shell.
Prerequisite ： Project start
DjangoSupport .Project start
DjangoSupport see ：【 to encounter Django】——（ One ） Create project - CoderChaos - Blog Garden (cnblogs.com)Four 、【PyCharm Use tips 】
Compared with from Terminal adopt python manage.py shell Get into Django shell, There will be a certain prompt when entering .
simpleui brief introduction Django Admin The default interface design language has some shortcomings , For example, the color is single , The use of a large number of lines , Segmentation is obvious . Categorizing these deficiencies is the monotonous interface 、 The similarity is obvious 、 Lack of surprises .
simpleui： Based on a vue+element-ui Of django admin The theme of modernization .
GitHub Address ：https://github.com/newpanjing/simpleui
simpleui Use poetry add -D django-simpleui
After installation , In my own project settings.py In file INSTALLED_APPS Of first line Join in simpleui.
# settings.py
INSTALLED_APPS = [
'simpleui',
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'polls'
]
If the previous service is still running , Refresh the page .
This article briefly introduces Django Connection and use with database , Use of the default background management interface .
And the use of PyCharm Quick operation makemigrations & migrate Command and django shell, Use django-simpleui Beautify the default background management interface .
