Hi Lance, Thanks for your comments.
On Jul 7, 2010, at 12:28 PM, Lance Edgar wrote: > Why not just do this in project2 ? > > > import project.DatabaseConnection as db > > Base = declarative_base(bind=db.engine) > > # ... etc. The DatabaseConnection class contains the particulars of the connection (i.e. host, username, password) which can be different. I don't want to create dependencies between the projects, I just want to reuse the class definitions. I want to create the DatabaseConnection once and "pass" it into the definition of the classes. Another approach I tried was to make ModelClasses an object and define the classes in a method there (so I could just pass the Base class to it), but the class definitions were in the wrong namespace. >> The "python way" seems to be to create a "config" class, but >> project2.ModelClasses won't know anything about it if it's defined in the >> first project. As to the reason why there are two separate projects, >> consider the case where one set of tables is one logical group, and the >> second is a replicated copy from another server. I can't merge all of these >> projects since they really are independent "units", but sometimes I will >> link them (as above). > > I don't understand why project2 wouldn't "know anything about it" if defined > in (first) project. All it needs to do is import the connection info from > the project (as in above example). If the database configuration really > transcends both project and project2 though, then yes it probably could be > wrapped in a config module of some sort in another project; depending on the > scope that may be a bit overkill. If you can consider either "project" or > "project2" to be slightly more default than the other then the db config > could stay there I'd think. This is a bit tricky to explain. Imagine I have one database, and I create a project (1) to work with that database (connections, table class definitions, etc.). That is standalone (to me). I have another completely separate database (2) on another host where I do the same thing. Using replication I then create a read-only copy of database 1 in database 2, and join some of the tables. Project 2 needs to generate the classes, but use SA's Base class that is dynamically generated. Since it's dynamic, I have to create it at run time... but now I can't pass that to the definition of project 1's classes. It's that communication that I'm struggling with. Cheers, Demitri -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
