Keeping python code and database in sync

[Rustom Mody]

On Friday, August 29, 2014 6:12:06 PM UTC+5:30, Frank Millman wrote:
> Hi all

> Now that I have bitten the bullet and published my repository, I am forced 
> to change my working practices (which is a good thing!).

> The project is inherently database-driven. The python code expects to find 
> certain tables and columns in the database. As I develop new features, I 
> sometimes need to modify the database structure. In the bad old days (like 
> yesterday) I would just make the modifications and carry on. Now I have to 
> be aware that others may have downloaded the project, so I have to consider 
> how to ensure that their database is kept up to date.


There are tools like this
http://alembic.readthedocs.org/en/latest/

It may help to read that to avoid reinvention



> It is a simple matter to write a program that updates the database 
> automatically. The question is, what should trigger such an update? My first 
> thought is to use a version number - store a version number in the working 
> directory, and have a matching number in the code. If someone downloads the 
> latest version, the numbers will no longer match, and I can run the upgrade 
> program.

> The problem with that is that version numbers are usually reserved for 
> tagged releases, but this could happen as the result of any commit in the 
> current development cycle.


I dont think alembic can solve that.
Still it may help to study it