Update django database to reflect changes in existing models

Question

I already defined the model and created the database associated with it through manager.py syncdb . Now that I have added several fields to the model, I tried syncdb again, but the output does not appear. When I try to access these new fields from my templates, I get a “No Such Column” exception, which makes me think that syncdb is not actually updating the database. What is the right team here?

Answer 1

It seems that you need a migration system. South is really nice, works great, there are some automation tools that make your workflow easier. And has an excellent tutorial .

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note: syncdb cannot update existing tables. Sometimes it’s impossible to decide what to do automatically - why the southern scripts are great.

Answer 2

Like Django 1.7+, built-in Django 1.5 )

If your changes violate your old scheme, this will not work - in this case tools like South or Django Evolution are great.

Answer 3

Starting with Django 1.7, you can do this with your own migrations. Just run

 python manage.py makemigrations <your app name> python manage.py migrate 

Answer 4

Django syncdb does not modify existing tables in the database, so you need to do this manually. As I always do this:

• Change the model class first.
• Then run: manage.py sql myapp.
• Look at the sql it prints out and see how it represents the change you are going to make.
• Make changes manually using the database manager.
• Make sure everything is working correctly using the admin site.

If you use sqllite, the firefox plugin is a good manager: link

Answer 5

Another tool will be the evolution of django. In most cases, a table reduction is not required.

django evolution

Just install it like any other django application and run:

python manage.py evolve --hint --execute

Answer 6

deseb is a great tool for this.

After installation, you can write. /manage.py sqlevolve and create the sql commands necessary to synchronize the database structure with your models.

Answer 7

You need to abandon your tables before you can recreate them with syncdb .

If you want to keep existing data, you need to unload your database, release your tables, run syncdb to create a new database, and then reload the old data into your new tables.

There are tools that help with this. However, in many cases, this is also easy to do manually.

Answer 8

For versions 1.4.1 and higher, the command has changed to

 python manage.py flush 

Read the white paper before using it as it will delete all your data .