如何使用新的Django迁移向模型添加新字段？ [英] How to add a new field to a model with new Django migrations?

问题描述

我正在使用 contribut_to_class 方法，但我不知道如何使用新的迁移在数据库中创建该字段。

I'm using the contribute_to_class method but I don't know how to create the field in the database with new migrations.

推荐答案

为了回答您的问题，随着Django 1.7中引入的新迁移，为了在模型中添加一个新的字段，您可以简单地将该字段添加到模型中，使用 ./ manage.py makemigrations 初始化迁移，然后运行 ./ manage.py migrate ，新的字段将添加到您的数据库。为避免处理现有机型的错误，您可以使用 - fake ：

To answer your question, with the new migration introduced in Django 1.7, in order to add a new field to a model you can simply add that field to your model and initialize migrations with ./manage.py makemigrations and then run ./manage.py migrate and the new field will be added to your db. To avoid dealing with errors for your existing models however, you can use the --fake:

1. 初始化现有模型的迁移：

1. Initialize migrations for your existing models:

./manage.py makemigrations myapp

现有模型的假迁移：

Fake migrations for existing models:

./manage.py migrate --fake myapp

添加来自myapp.models的新字段：

Add the new field to myapp.models:

from django.db import models

class MyModel(models.Model):
... #existing fields
newfield = models.CharField(max_length=100) #new field

/ li>

再次运行makemigrations（这将在迁移文件夹中添加新的迁移文件，将新的字段添加到db）：

Run makemigrations again (this will add a new migration file in migrations folder that add the newfield to db):

./manage.py makemigrations myapp

运行迁移再次：

Run migrate again:

./manage.py migrate myapp

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