ZEXI JIN

Django directory levels

1. manage.py: we use this to communicate with Django server
2. project directory:
   1. __init__.py: tells Django to use directory as a python package
   2. settings.py: Django configuration file
   3. urls.py: url schema
   4. wsgi.py: project and wsgi integration web server

Database (MySQL) config

• dependencies used:
  mysql 5.7.24 h56848d4_0
  mysql-connector-c 6.1.11 hccea1a4_0
  mysql-connector-python 8.0.17 py27h3febbb0_0 anaconda
  mysql-python 1.2.5 py27h1de35cc_0 anaconda
  pymysql 0.9.3 py27_0
• __init__.py:, add the following code:

  import pymysql
  pymysql.install_as_MySQLdb()

• in settings.py: add database configurations to connect to the database

  DATABASES = {
      'default': {
          'ENGINE': 'django.db.backends.mysql',
          'NAME': # server name
          'USER': # user name
          'PASSWORD': # password
          'HOST': 'localhost',
          'PORT': '3306',
      }
  }

Init new application

• init new application:

  python manage.py startapp <myApp>

• codes above creates:
  • admin.py: website config
  • models.py: model
  • views.py: view
• In setting, add to INSTALLED_APP:

  INSTALLED_APPS = [
      'django.contrib.admin',
      'django.contrib.auth',
      'django.contrib.contenttypes',
      'django.contrib.sessions',
      'django.contrib.messages',
      'django.contrib.staticfiles',
      'myApp'
  ]

models.py file

• the following is an example of models.py

  # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  from django.db import models
  
  # Create your models here.
  class Grades(models.Model):
      gname = models.CharField(max_length=20)
      gdate = models.DateTimeField()
      ggirlnum = models.IntegerField()
      gboynum = models.IntegerField()
      isDelete = models.BooleanField(default=False)
      
      def __str__(self):
          return "%s-%d-%d"%(self.gname, self.gboynum, self.ggrilnum)
  
  
  class Students(models.Model):
      sname = models.CharField(max_length=20)
      sgender = models.BooleanField(default=True)
      sage = models.IntegerField()
      scontend = models.CharField(max_length=20)
      isDelete = models.BooleanField(default=False)
      sgrade = models.ForeignKey("Grades")
      
      def __str__(self):
              return "%s-%d-%s"%(self.sname, self.sage, self.scontend)

• make migration and execute migration file: will create database according to models.py

  python manage.py makemigrations # create migration file
  python manage.py migrate        # execute migration file

To add new entries with manage.py shell commands

1. enter shell:

   python manage.py shell

2. import packages in shell:

   from myApp.models import Grades, Students
   from django.utils import timezone
   from datetime import *

3. add new entry to db:

   grade1 = Grades()
   grade1.gname = "something"
   grade1.gdate = datetime(year=,month=,day=)
   grade1.ggirlnum = 70
   grade1.gboynum = 35
   grade1.save()

4. some other command:

   Grades.objects.all()    # get all data entries in Grades
   g = Grades.objects.get(pk=1)    # get the 1st object in Grades
   g.gboynum = 45
   g.save()    # alternate existing data
   d.delete()  # delete, including the one in db
   stu1 = g.students_set.create(sname=...)     # add new student with one line

To run server

• execute:

  python manage.py runserver ip:port

• Admin:
  • publish content
  • add/modify/delete content
  • add “‘django.contrib.admin’” in INSTALLED_APPS
  • exists by defualt
  • add “/admin” and log in
  • change language or timezone based on preference

(to be continued…)