Add multiple-database support

[hartbit]

The way it works right now, FCModel is implemented as a bunch of class methods, relying on private global variables. It's kind of convenient, but not as flexible as I'd like. This has caused me a few issues when I wanted to open more than one database at once (for example).

Wouldn't it be more flexible to separate the library into FCModel, the subclass of all database table/classes, and a FCDatabase or FCManager, that handles the connection to one database?

[LukeDurrant]

What scenario requires you to have two sql databases?
Sorry not helpful! Just curious

[hartbit]

I have a scenario where I need to have one database per user, and I'd also like to have one database with non-user data. So, I need to have two databases open at all times. One for user-data and one for non-user data.

And the reason I need one database per user, is I need to encrypt them (SQLCypher) with the user's password.

[johncblandii]

This was the first thing I asked Marco when I started using FCModel. We had a similar need but went without the multiple. I could easily see your scenario creeping into our app as well.

(Will delete other duplicate comment in the morning)

[marcoarment]

I just added a closeDatabase call, which isn't really what you're asking for, but might get you partly there.

I'm not sure if full-fledged multiple-database support is worth the complexity. It would require a lot more code and a lot of tiny but frequent lookups and checks. If it ends up that a lot of people really need this, it may be worth adding, but I'm not sure it's really needed that badly by most people.

Let's discuss use-cases where multiple databases are the only reasonable option to try to get an idea of how common and necessary they really are.

@hartdev: Could you just put everything in the encrypted DB? Are multiple users being logged in simultaneously in your app?

@johncblandii: Has using the combined database been problematic or particularly awkward for you?

[johncblandii]

@marcoarment, no. I was able to get us to move away from that need. There is a definite possibility of it returning though but for now NSUserDefaults is our friend, since data security isn't an issue. Our databases are specific to a user by name though.

It definitely adds complexity for multiple DBs. Worst case scenario, use FCModel for the user db and just direct FMDB for the other one; in other words, your app supports multiple DBs but not FCModel. Odd, I know, but feasible now without complicating FCModel.

[marcoarment]

Based on this discussion, I think it's best to keep FCModel single-database for now. Feel free to discuss again in the future.

[paventuri]

+1

I have a database using SQLCipher and a General database.

It would be perfect to have FCModel supporting multiple-database.