1.前言：

將測(cè)試數(shù)據(jù)全部敲入數(shù)據(jù)庫(kù)非常繁瑣，而且如果與合作伙伴一起開(kāi)發(fā)，部署，那么他們肯定也不想把時(shí)間花在一個(gè)一個(gè)錄入數(shù)據(jù)的繁瑣過(guò)程中，這時(shí)候，創(chuàng)建一個(gè)批量錄入數(shù)據(jù)的腳本（population script)就非常有必要。

2.代碼：

假設(shè)在models.py中定義的數(shù)據(jù)為下面：

from django.db import models # Create your models here.class Category(models.Model): name=models.CharField(max_length=128,unique=True) class Meta: verbose_name_plural='Categories' def __str__(self): return self.name class Page(models.Model): category=models.ForeignKey(Category,on_delete=models.CASCADE) title=models.CharField(max_length=128) url=models.URLField() views=models.IntegerField(default=0) def __str__(self): return self.title

populate.py如下（僅供參考）：

import os# In your live server environment, you’ll need to tell your WSGI application what settings# file to use. Do that with os.environ:#reference source:https://docs.djangoproject.com/en/3.1/topics/settings/os.environ.setdefault(’DJANGO_SETTINGS_MODULE’,’tango_with_django_project.settings’) import djangodjango.setup()from rango.models import Category,Page#If you’re using components of Django “standalone” ? for example, writing a Python script# which loads some Django templates and renders them, or uses the ORM to fetch some data ?# there’s one more step you’ll need in addition to configuring settings.# After you’ve either set DJANGO_SETTINGS_MODULE or called configure(), you’ll need to call# django.setup() to load your settings and populate Django’s application registry.# reference source:https://docs.djangoproject.com/en/3.1/topics/settings/def populate(): python_pages=[ {'title':'official', 'url':'http://docs.python.org'}, {'title':'How to think like a computer scientis', 'url':'http://ww.greenteapress.com/thinkpy'}, {'title':'learn python in 10 minites', 'url':'http://www.korokithakis.net/tutorials/python'} ] django_pages=[ {'title':'Official Django tutorial', 'url':'https://docs.jangoproject.com/en/1.9/intro'}, {'title':'Django Rocks', 'url':'http://www.djangorocks.com' }, {'title':'HOw to tango with django', 'url':'http://www.tangowithdjango.com'} ] other_pages=[ {'title':'Bottle', 'url':'http://bottlepy.org'}, {'title':'Flask', 'url':'http://flask.pocoo.org'}, {'title':'Bold test', 'url':'http://boldtest.org'} ] cats={'Python':{'pages':python_pages}, 'Django':{'pages':django_pages}, 'Other Frameworks':{'pages':other_pages}} def add_page(cat,title,url,views=0): p=Page.objects.get_or_create(category=cat,title=title,url=url,views=views)[0] # p.url=url # p.views=views p.save() return p def add_cat(name): c=Category.objects.get_or_create(name=name)[0] c.save() return c for cat,cat_data in cats.items(): c=add_cat(cat) for p in cat_data[’pages’]: add_page(c,p['title'],p[’url’]) for c in Category.objects.all(): for p in Page.objects.filter(category=c): print('-{0}-{1}'.format(str(c),str(p))) if __name__=='__main__': print('starting rango population script') populate()

　3.代碼要點(diǎn)

（1）在獨(dú)立運(yùn)行django的代碼時(shí)，而不是通過(guò) python manage.py runserver的方式運(yùn)行時(shí)，必須使用django.setup()來(lái)引入Django項(xiàng)目的設(shè)置，而在引入設(shè)置之前還要指明 環(huán)境變量DJANGO_SETTINGS_MODULE用的是本項(xiàng)目的settings。

設(shè)置環(huán)境變量在python中常用os.environ，它返回一個(gè)字典類(lèi)型，里面包含了所有環(huán)境變量的鍵值對(duì)，所以在這里使用字典的內(nèi)置方法setdefault，將環(huán)境變量

’DJANGO_SETTINGS_MODULE’ 設(shè)置為’tango_with_django_project.settings’（本項(xiàng)目的settings.py）。<br>參考：<a rel='external nofollow' >https://docs.djangoproject.com/en/3.1/topics/settings/#envvar-DJANGO_SETTINGS_MODULE</a>

（2）get_or_create方法：（官方文檔定義https://docs.djangoproject.com/en/3.1/ref/models/querysets/#get-or-create如下）

get_or_create(defaults=None, **kwargs)A convenience method for looking up an object with the given kwargs (may be empty if your model has defaults for all fields),<br> creating one if necessary.Returns a tuple of (object, created), where object is the retrieved or created object and created is a boolean specifying whether a new <br>object was created.This is meant to prevent duplicate objects from being created when requests are made in parallel, and as a shortcut to boilerplatish code. <br>

　在這里，需要注意的是，如果在創(chuàng)建model instance時(shí)，僅在model有默認(rèn)值的情況下可以不輸入任何kwargs，否則必須至少輸入一個(gè)值（field,如這里page的category，或者Category的name)，然后該方法會(huì)帶著這個(gè)值先去找有沒(méi)有該值下的model instance，如果沒(méi)有則創(chuàng)建一個(gè)新的，返回（object,created)，這里object 是新創(chuàng)建的對(duì)象的reference，created為T(mén)rue.

4.運(yùn)行查看

運(yùn)行python populate.py：

然后登陸admin頁(yè)面查看：

可以看到，數(shù)據(jù)全部被讀入數(shù)據(jù)庫(kù)。

以上就是Django如何批量創(chuàng)建Model的詳細(xì)內(nèi)容，更多關(guān)于Django批量創(chuàng)建Model的資料請(qǐng)關(guān)注好吧啦網(wǎng)其它相關(guān)文章！