How strict should ToSql and FromSql be?

[sfackler]

This will become much more relevant when issue #7 is implemented. FromSql for float may have to be able to deal with numerous kinds of integer binary data if we want to be forgiving about conversions.

[sfackler]

I'm leaning towards making both ToSql and FromSql strict. An i32 value maps to and from an INT value, f32 values map to and from REAL, etc. Supporting #7 is otherwise an enormous pain since the backend tells the frontend what types it expects to receive and will return. This will require a reasonable API to expose the types of parameters and results to support dealing with types that aren't known ahead of time to the programmer.