Django 学习笔记(5)

上一小节总结了下数据库的连接配置，实际上由于安装python的版本，上一节配置失败了。

这一节就总结下模型的使用。由于练习是在白天进行的，所以晚上我只记录下过程即可。大部分无截图。

1 在D:\mysite\mysite\books\models.py文件中编辑添加如下内容：

from django.db import models

# Create your models here.

class Publisher(models.Model):
    name = models.CharField(max_length=30)
    address = models.CharField(max_length=50)
    city = models.CharField(max_length=60)
    state_province = models.CharField(max_length=30)
    country = models.CharField(max_length=50)
    website = models.URLField()
    def __unicode__(self):
        return self.name

  

class Author(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=40)
    email = models.EmailField()
    def __unicode__(self):
        return self.first_name
    
class Book(models.Model):
    title = models.CharField(max_length=100)
    authors = models.ManyToManyField(Author)
    publisher = models.ForeignKey(Publisher)
    publication_date = models.DateField()
    def __unicode__(self):
        return self.title

 

2 修改D:\mysite\mysite\sittings.py文件，按照如下方式编辑：

INSTALLED_APPS = (
    #'django.contrib.admin',
    #'django.contrib.auth',
    #'django.contrib.contenttypes',
    #'django.contrib.sessions',
    #'django.contrib.messages',
    #'django.contrib.staticfiles',
    'mysite.books',
)

MIDDLEWARE_CLASSES = (
    #'django.contrib.sessions.middleware.SessionMiddleware',
    #'django.middleware.common.CommonMiddleware',
    #'django.middleware.csrf.CsrfViewMiddleware',
    #'django.contrib.auth.middleware.AuthenticationMiddleware',
    #'django.contrib.messages.middleware.MessageMiddleware',
    #'django.middleware.clickjacking.XFrameOptionsMiddleware',
)

3 在cmd中进入到d:\mysite目录下，执行python manage.py validate命令。可以看到如下提示：

D:\mysite>python manage.py validate
0 errors found

4 再执行python manage.py sqlall books命令，查看生成的sql 。可以看到如下提示：注意，这里仅仅是打印出来。

D:\mysite>python manage.py sqlall books
BEGIN;
CREATE TABLE "books_publisher" (
    "id" integer NOT NULL PRIMARY KEY,
    "name" varchar(30) NOT NULL,
    "address" varchar(50) NOT NULL,
    "city" varchar(60) NOT NULL,
    "state_province" varchar(30) NOT NULL,
    "country" varchar(50) NOT NULL,
    "website" varchar(200) NOT NULL
)
;
CREATE TABLE "books_author" (
    "id" integer NOT NULL PRIMARY KEY,
    "first_name" varchar(30) NOT NULL,
    "last_name" varchar(40) NOT NULL,
    "email" varchar(75) NOT NULL
)
;
CREATE TABLE "books_book_authors" (
    "id" integer NOT NULL PRIMARY KEY,
    "book_id" integer NOT NULL,
    "author_id" integer NOT NULL REFERENCES "books_author" ("id"),
    UNIQUE ("book_id", "author_id")
)
;
CREATE TABLE "books_book" (
    "id" integer NOT NULL PRIMARY KEY,
    "title" varchar(100) NOT NULL,
    "publisher_id" integer NOT NULL REFERENCES "books_publisher" ("id"),
    "publication_date" date NOT NULL
)
;
CREATE INDEX "books_book_authors_36c249d7" ON "books_book_authors" ("book_id");
CREATE INDEX "books_book_authors_e969df21" ON "books_book_authors" ("author_id")
;
CREATE INDEX "books_book_81b79144" ON "books_book" ("publisher_id");

COMMIT;

D:\mysite>

5 执行python manage.py syncdb命令，将会执行如上sql。另外，这个命令针对模型的修改删除，并不会同步到数据库中。

6 按照如下的方式执行，数据已经创建。可以查看到该表的数据。

D:\mysite>python manage.py shell
Python 2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from mysite.books.models import Publisher
>>> Publisher.objects.all()
[, ]
>>>