xdevapi - dynamic queries - multiple queries

[Ian James]

I'm working on converting a project from using the legacy JDBC connector to xdevapi. I know I can replicate what I'm doing right now using the session.sql classes and functions. However, I'd like to use the CRUD operations described in the documentation. That said, I can't figure out any way to create dynamic queries - ie. a select statement where I don't know how many columns will be needed at compile time. I thought perhaps I could call select("column_name") functions before doing .execute(), but that didn't work. I also considered perhaps I could use a vector of strings, but that wasn't accepted either. Any help here?

My other question, is there a way to send multiple queries to the database at once? The database is on a server, its not necessarily local, and the mysql queries are the most expensive thing the program does. Sending multiple queries at once makes things considerably more efficient, but I didn't see any documentation on that.

Thank you in advance!