Support for SQLite3

[ak-gupta]

I tried to connect to a local SQLite3 database using Locopy and it threw the following error:

ValueError: parameters are of unsupported type

After doing some digging, it looks like the error is being thrown by the default argument in locopy.database.Database.execute() for params. Once I started using params=(), it started working.

e.g.

with locopy.Database(dbapi=sqlite3, database=':memory:') as cmd:
  cmd.execute('''CREATE TABLE stocks (date text, qty real)''', params=())

I tested params=() with locopy.snowflake.Snowflake as well and it worked.

[jborchma]

To be fair, there are already a lot of SQLite packages out there. I wonder if this should be really the scope of locopy.

[fdosani]

I'm ok with this if it extends support to other DBAPI 2.0 adapters. I don't think we'd add loading / unloading functionality but just to use the execute should be fine especially if it is just tweaking params. @ak-gupta Did you want to propose a PR with tests for this?

[ak-gupta]

@jborchma Yeah I agree with your point. I guess I was more focused on whether or not the current default params=None is correct given that it has no impact on Snowflake queries and it allows users to query SQLite databases.

@fdosani Yes I was thinking the same; it's probably out of the package scope to add a new Database subclass. I can work on a PR

[fdosani]

@ak-gupta any traction on this feature? No pressure, just wondering if you needed a hand

[ak-gupta]

Sorry, I didn't have a chance to work on this until recently. I've made the changes and it looks like the tests are running nicely! I'll submit a PR once I've done another sweep.