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 contribute_to_class 方法，但我不知道如何使用新迁移在数据库中创建字段.

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，通过 Django 1.7 中引入的新迁移，为了向模型添加新字段，您可以只需将该字段添加到您的模型并使用 ./manage.py makemigrations 初始化迁移，然后运行 ​​./manage.py migrate，新字段将添加到您的数据库中.

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.

然而，为了避免处理现有模型的错误，您可以使用--fake:

To avoid dealing with errors for your existing models however, you can use the --fake:

1. 为现有模型初始化迁移:

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

将新字段添加到 myapp.models:

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

再次运行 makemigrations(这将在将新字段添加到 db 的迁移文件夹中添加一个新的迁移文件):

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

./manage.py makemigrations myapp

再次运行迁移:

Run migrate again:

./manage.py migrate myapp

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