问题
I am using Django to build a website with MySQL. Now as I am learning so I need to change the Model very often so I want that all tables get cleared and new table get created.
But syncdb doesn't touch existing tables. Is there any better way to handle this problem?
回答1:
If you don't care about data:
Best way would be to drop the database and run syncdb again. Or you can run:
For Django >= 1.5
python manage.py flush
For Django < 1.5
python manage.py reset appname
(you can add --no-input to the end of the command for it to skip the interactive prompt.)
If you do care about data:
From the docs:
syncdb will only create tables for models which have not yet been installed. It will never issue ALTER TABLE statements to match changes made to a model class after installation. Changes to model classes and database schemas often involve some form of ambiguity and, in those cases, Django would have to guess at the correct changes to make. There is a risk that critical data would be lost in the process.
If you have made changes to a model and wish to alter the database tables to match, use the sql command to display the new SQL structure and compare that to your existing table schema to work out the changes.
https://docs.djangoproject.com/en/dev/ref/django-admin/
Reference: FAQ - https://docs.djangoproject.com/en/dev/faq/models/#if-i-make-changes-to-a-model-how-do-i-update-the-database
People also recommend South ( http://south.aeracode.org/docs/about.html#key-features ), but I haven't tried it.
回答2:
Using Django Extensions, running:
./manage.py reset_db
Will clear the database tables, then running:
./manage.py syncdb
Will recreate them (south may ask you to migrate things).
回答3:
I think Django docs explicitly mention that if the intent is to start from an empty DB again (which seems to be OP's intent), then just drop and re-create the database and re-run migrate (instead of using flush):
If you would rather start from an empty database and re-run all migrations, you should drop and recreate the database and then run migrate instead.
So for OP's case, we just need to:
- Drop the database from MySQL
- Recreate the database
- Run
python manage.py migrate
回答4:
Quickest (drops and creates all tables including data):
./manage.py reset appname | ./manage.py dbshell
Caution:
- Might not work on Windows correctly.
- Might keep some old tables in the db
来源：https://stackoverflow.com/questions/6485106/what-is-the-easiest-way-to-clear-a-database-from-the-cli-with-manage-py-in-djang